Secondary cat delete

[tmontague]

Hey guys,

I'm getting a custom exhaust installed early next week. The guy doing the work (trusted and knowledgeable) recommended a secondary cat and resonator delete with 2.5" piping and an aftermarket exhaust.

He stated I won't lose low end torue but will increase top end HP due to my other mods (intake header etc).

He also stated that my CEL wouldn't get triggered because the O2 sensor only reads after the first cat so the second one has no effect on a CEL being triggered.

Can someone please chime in on this. I don't want to go through the work and then have to re install my second cat due to a CEL. If the CEL will get triggered then I'll just do a resonator delete instead.

Thanks

[Jason@SportsCar]

2.5" is to big if you are running NA, you will lose tq, 2.25" is plenty big. I would not pull the cat on a road going car, if you want to make noise pull the resonator.

[tmontague]

Thanks Jason. The exhaust guy said he could do either 2.25 or 2.5 but he recommended 2.5. Will the secondary cat delete change the sound to you more deeper tone? I'm looking for performance as well as a deeper ton but not an obnoxious fart can noise that just sounds dumb.

If there is not CEL w/ a secondary cat delete then I have no prob with it. If I have a CEL then it become problematic for me. It makes sense that no CEL would be thrown since there is no O2 sensor after the secondary cat to trigger it.

[Rigaud]

I did 2.25, based on displacement and hp with an n/a engine. If you where recommended 2.5" don't do it and forget this guy. Jason's advice is spot on. I used a free flow 6" diameter muffler as a resonator and one free-flowing cat up front. The sound is deep not tin can. I already posted this several times elsewhere.

[tmontague]

What is the issue with removing the secondary cat (other than pollution)?

I searched the forums but never found your thread

[WeeYari]

I seem to recall some discussion from ages ago regarding pipe sizing. 2.25" if mandrel bent, up to 2.5" if crush bent.

[Rigaud]

What is the issue with removing the secondary cat (other than pollution)?

I searched the forums but never found your thread
No issue with one cat as long as your car has one and it's approved! I'll find the part numbers from my set up later this evening and PM you the info.

As for 2.5" crush bent....................NO, just no. You seem like a guy who wants to do things right!! ;)

[tmontague]

No this guy's stuff is all mandrel bent. At this point it's looking like i'm going to go 2.25" with the secondary cat and resonator delete with aftermarket muffler.

I'm going to ask him why he thinks it's worth getting rid of the secondary cat. He had briefly mentioned that it doesn't do a whole lot since the primary one is there. He also said it will just help with lowering the tone of the exhaust and allow for less restriction overall.

[Fluxtasy]

Hi all, I'm driving a Vios/Yaris sedan matic and just had the 2nd cat removed before the resonator and replaced with a piping of the same diameter. It does feel less restrictive and some lightness to the pedal.

I'm just wondering if there is any difference if I had the 1st cat delete instead of the 2nd cat?

[tmontague]

Performance wise, i'm not sure, maybe a slight difference. The stock cat are not very restrictive to begin with.

How ever w/ out the primary cat you'll throw a CEL and not come close to passing emissions (not sure if you have those or not). The primary cat does most of the emissions work as it gets very hot, the secondary not so much.

[Fluxtasy]

Testing is only required if I sell/transfer ownership of the car. No CEL from my 2nd cat delete.

The guy at the exhaust place told me I could remove both cats if I wish but since I'm running the stock muffler so the sound would be horrible (air rushing through a hollow tin can). Anyway I think he removed the 2nd cat as it is a easier job than removing the 1st cat. Just wondering if there would be any improvements if I had the 1st cat deleted instead of the 2nd.

[SirDigby]

wow. I've never looked at the exhaust system. what a bunch of garbage!

[WeeYari]

wow. I've never looked at the exhaust system. what a bunch of garbage!


??


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[tmontague]

Finally got my exhaust complete! Picked it up last night and have driven about 150km on it so far.

I got the work done at Techtune in Etobicoke/TO. around 427/Gardener area. I was recommended to go there from my buddy who got his Jeep done there and his cousin who performance tunes/builds Mitsubishi Eclipses and currently owns an 800whp AWD eclipse he built himself that actually runs/races (true story). Bottom line, my recommendations were well sound.

I called JPG exhaust in Oakville first since they're closer to me and they had done simple fix up work on my Echo. Quoted $450 for SS and a simple resonator back exhaust. The guy was rushed on the phone and never offered any recommendations to me.

I called Techtune and the owner picked up. He gave me recommendations and even knew right away without me telling him that the Yaris had 2 cats and only the 1st one is used for emissions and has a downstream O2 sensor. He quoted me $250 for a full Primary cat back exhaust using aluminum. It would have been $400-$450 for SS.

When I got there around noon yesterday the owner was busy working on a car so I spoke with his assistant mechanic (a younger guy). The assistant did not know what the older guy told me on the phone the day before, all he knew is that I told him I spoke with the owner yesterday. He lifted up my Yaris and had me go under it with him and walk him through what I thought I wanted.

I told him I wanted 2.25" and he asked why I didn't want 2.5". I explained potential issues brought up on this forum regarding torque. I asked his opinion because I wanted to know what he thought and why he thought 2.5" was better than 2.25". Most of the info on this forum was here say and theoretical and the same with any other forums. I highly value and appreciate the experience and input on this forum, but I wanted to hear what Tech tune's reasoning was for going 2.5" and what their experience was in the real world.

Worst case scenario I could always switch back to 2.25" if needed. The assistant mechanic said that because I had an aftermarket header (he also asked/looked at the other engine mods I had done) it would create the restriction I needed for back pressure. He said the 2.5" would allow for the gases to expel better at very high rpm like on high way speed downshifts (which is where I felt the Yaris lags). So basically the header creates enough of the backpressure needed for the low end torque, but the 2.5" pipes allow for the top end clearing need for high rev power.

I weighed this with the advice on the forum and decided to opt for the 2.5". The whole time I spoke with the mechanics at Techtune they were always very confident and helpful, they never seemed to second guess themselves or act unsure. That being said they weren't pressing or judgmental if I wanted to do something different it just seemed like they were offering genuine advice.

Now I'm a 25 year old grad student who's getting married this summer and will likely have a baby in a year or two. I was looking for performance primarily but also wanted some noise when really throwing down the throttle. The stock exhaust is dead silent and I couldn't stand that. The last thing I wanted was a fart can that has a high pitched buzz throughout the whole rev range. I want to keep my Yaris somewhat classy and make it as much fun as possible. The mods I do on my car are for my own enjoyment, experience and learning not for others recognition.

The mechanics recommended to remove the 2nd cat and resonator and put on a turbo exhaust. They said if it's too loud then they'd just install the resonator back on for me for free, but recommended to try it without the resonator first.

The new exhaust is much louder than stock obviously but it's different than what I've heard in other 4 bangers around where I live. It has a rumble sort of like the Subie rumble. Now obviously not the same as the Subie rumble as nothing sounds that good ;) but I notice that if I rev it at idle it rumbles/burble's nicely. It doesn't get louder and louder as the revs climb either. I find it is actually louder if I try and low shift around 2,000rpm vs shifting at 3000rpm. It is initially loud when starting to accelerate but sort of settles in as the rpm's climb.

If I drive on the highway under 3000rpm it sounds similar to stock. When I go above 3000rpm you can hear it. I don't find it annoying like a drone per say but it is louder than a typical quiet commuter car.

I haven't really noticed any torque loss yet. I still need more time driving the car though before I can confirm any changes. The Yaris pulls much better now around 5,000rpm and above. It no longer seems to plateau after 4500rpm it just pulls hard and you can hear the engine screaming now. The engine now finally has full flow of air in and out from the intake all the way down to the exhaust.

It's a shame you can't tune these cars but it is what it is and that's also what makes them last so long.

The exhaust tip looks clean out the back it is larger than stock and is a somewhat rounded square shape. I didn't pay extra for a larger one as I personally don't like the look of the massive oversize tips.

I chose aluminum as it fit my budget at the moment. I also didn't feel that almost double the price was worth it for SS. When the aluminum wears out I could always change the exhaust to something different if I wanted and it is relatively inexpensive. 5-7 years out of aluminum would be great I don't need 10+ years out of it if I'm only paying $250 for it. I drive my car often so the exhaust is constantly hot enough to dry out as well.

I will be putting my car on ramps later this week to take picstures and check what type of bends they used. My buddy told me that he was sure they did mandrel bends but I never actually asked the mechanic. I know they aren't the ripple type crush bends, but I'm not sure 100% if they are mandrel bent or not.

They also sprayed the exhaust with silver spray paint after wards which makes it look pretty nice.

I'm thinking I should paint the exhaust this weekend to help protect it longer, but I'm not sure how well that will actually help it. I have some high temp black paint left over so I may give it a go. We'll have to see. If anyone has any advice on that let me know.

All in all I'm damn pleased with the performance, sound and work done. I only paid $250 which I think is a great price and considering what i paid, I think it was well worth it. I likely could have sourced an exhaust place that had the highest grade SS and had full mandrel bends etc, but I would have paid well over what I was willing. I was more than pleased to pay their asking price for the work and was happy with what i was able to get done.

I would highly recommend Techtune's work. I hate taking my Yaris to mechanics as I only trust myself with my car, but I never once felt uncomfortable or untrusting of them. They know what they're doing and I can see why a lot of Porsche and Audi guys take their cars there. If you live in the area I'd seriously consider some sort of aftermarket exhaust from them.

Before I left after dropping my car off I mentioned if they could keep the stock parts they remove in case I ever need it back to stock. They said no problem. When I picked up my car outside their shop hours after they closed, the removed pieces (bolts and all) were all placed neatly in the trunk and they even put a garbage bag down so it didn't dirty anything up. That was nice to see, especially when the Toyota dealership a couple years ago decided my non oem floor mat wasn't safe when doing recall work and decided to just toss it on the back seat dirt and all...

I'll post pics and a sound clip up by this weekend. Fire away if you have any Q's

FWIW my fiancee can't stand high pitched fart cans but mentioned that she could hear me coming home from the street over last night. She mentioned that she doesn't find it annoying or high pitched but more or a loud burble that she said sounded nice.

[WeeYari]

I take it all new work is welded right in. No flanges?

[tmontague]

All welds except for a curved pipe going over the axle. It isn't a flange per say but a clamp.

So essentially from back to front you have muffler, u clmap, upside down u shaped pipe going over axle, u clamp and then long 2.5" pipe welded into primary cat.

Also there are other welds near the muffler so the actualy muffler is more to the front of the car than the stock one. So there is about 1-2' of pipe from the muffler to the tip. This aids in lowering lowering pitch.

I'm assuming this is due to being able to install it as a whole piece since the axle is in the way.

Everything else is welded

[WeeYari]

Can't recall if sedan and hatch share the same components forward of the axle. I have a hole in my resonator and would be willing to buy yours if you opt to never put it back in.


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[tmontague]

I'm pretty sure the sedan and hatch are the same forward of the axle. I'll be sitting on the resonator for a bit until the exhaust tone settles in over the next couple months. After that I would sell it to you if the price if worth it (not sure what they go for).

I was going to hold onto it in case I ever needed to go back to stock or wanted to tone the noise down. That being said, I won't ever need to go back full stock as I don't think I'll ever sell my Yaris and so far I'm pleased with the sound.

[Rigaud]

No it wasn't hearsay but based on experience from several people here. Your exhaust is measured from CFM going in and out and you need some back pressure. By going too big you lose back pressure. I did mine based on maximum cfm, max hp I could ever get out of this 1.5L N/A. Before I did mine every custom shop wanted to convince me to do 2.5"............it's more common and in stock. Been doing this for 33 years, I did my share of mistakes when I was a kid but didn't have internet or anything much like in today's world.

2-1/4" pipes 408 cfm 185hp single
2-1/2" pipes 509 cfm 232hp single

Your engine put's out 106 HP at the motor and about 89whp.

Even Jason who races these cars gave you good info. ;)

This will be my last post for info.

Cheers

[tmontague]

Fair point. Hearsay was the wrong word, it was statements given from experience of other people that either had heard it from others or just knew based on their own knowledge.

What I meant was that no one that I had read about or heard from had actually ran a 2.5" exhaust on the Yaris and actually lost torque. Now this could be because the people that ran exhausts knew better and went w/ a lower diameter.

I did a lot of reading regarding CFM's etc and even then I still found conflicting advice unfortunately. In the end I chose to go with the mechanics advice as his rationale seemed sound.

If I find that I have in fact lost some low end, then in a year or two i'll have 2.25" pipes put in and then I can better experience the difference myself. Some things I need to experience myself before I can make a confident choice on what is better suited for me.

I'll keep this thread updated as I drive more so anyone down the road doing exhaust work can read about it and help them make their own decision.

The moral of the story very well could be that people on a specific car forum will know more about the said car than an experienced multi car mechanic. Time will tell

[LTHatch]

Glad to see you went outside the normal and experimented with a larger exhaust, the impressions and feedback you provide will help other folks in the future who wonder about a larger exhaust.
How is the engine response and torque between 2-3k rpm's?
At cruising highway speeds, do you pass other cars without downshifting or with less throttle then before?
How many miles have you put on the new system and did you do a ECU reset?

[jmanous]

Can anybody comment on why loosing backpressure is bad?

I would imagine that going with a larger pipe will result into lower gas speed
at low RPM, with that been the cause of loosing some power at this band.

[tmontague]

Thanks LTHatch, even when searching other forums I hadn't read more single case where someone actually experienced loss of torque from going to big so I wanted to see for myself.

I didn't reset the ECU when the exhaust was installed, not sure I that would do anything to not as the ECU is constantly updating as you drive. No CEL has been thrown which was expected.

To answer your Q's plus a bit of an update after about 300km or so here is some more info:

I notice I have to depress the pedal down a bit more when low shifting (~2000-2300rpm) as well as when in 5th it "seems" (need more driving to confirm) that the car isn't accelerating as fast as it did after my TB and Manifold port mod.

I'm going to do some high Rev shifts today to test it out more, but so far i"ve noticed a much faster pull at higher rpm's (around 4500+). Basically it seems to get to the redline faster than it use to.

In Summary:

Potential loss of low end torque between 2000 and 2700rpm
Gain in torque from 4500+rpm
No change noticeable from 3000-4500rpm

I actually am going back to Techtune next Tuesday for 2 reasons. The first being that when I hit large bumps (going into a driveway fast) the rear axle slightly hits the exhaust and the second being to get 2.25" pipes installed.

The owner I spoke with said that he'll install 2.25" pipe over the axle as it will allow a sharper bend than the 2.5" and that there is a lot of room there for him to work with still.

He said that would also increase back pressure to help torque. I just told him I'd rather just get 2.25" throughout an d he said no problem but that it will slightly change the noise. He said it won't make it quieter but it will clean up the "dirtyness" of the noise a bit.

I'm still going to keep my resonator off for now as I do like the burble right now and my fiancée surprisingly likes it to.

Now i'll get to compare how a 2.25" pipe is like which i'm looking forward to. From doing much more reading on exhaust i've come to the understanding that it no really back pressure that you want but velocity. Going too large a pipe reduces velocity which therefore reduces exhaust scavenging.

I understand I can't get the best of both worlds (high rpm hp and low end torque) but 2.25" might be the best middle ground where 2.5" gains are minimal in th top end over 2.25" but you take a larger loss on the low end torque.

The 2.5" pipe essentially felt like I went back to stock from the torque gain I got from my DC header. It's not a large loss at all, and probably not noticeable to most people. I use my Yaris Yaris a DD so I enjoy more low end torque. I am not running my engine at 6000rpm f an hour like people who track their car do. Other than some very spirited drivind each week in the country and a handful of hard pulls, I gain more from low end torque.

I'm looking forward to seeing the difference with the 2.25" installed. That will confirm others knowledge/experience on this forum that chimed in and offered advice. I'm just curious as to how large the torque difference is.

[tmontague]

Can anybody comment on why loosing backpressure is bad?

I would imagine that going with a larger pipe will result into lower gas speed
at low RPM, with that been the cause of loosing some power at this band.

Here's my take on it after a ton of reading from various viewpoints:

You don't want back pressure as this would slow down exhaust scavenging. Back pressure is often a misused term. You want exhaust velocity, this is what creates negative pressure and "pulls" or scavenges exhaust gases out of the engine.

Velocity is changed with diameter shape/size. Too narrow a pipe and back pressure increases which leads to slow exhaust velocity and poor scavenging and therefore a hindrance on performance. Too large a diameter and you also lower exhaust velocity even though there is little resistance to to exhaust gases to exit.

Think of a large hose with water flowing through like a garden hose. Assuming that the power of the water being pushed through the hose is always the same the only change in speed of the water comes from the diameter of the hose. The same amount of water will exit (unless the hose becomes way too small) but too large a hose and the water slows down. Too small and you reduce the amount of water that can exit. The right size is one that causes the water to increase it's speed (velocity) without being restrictive.

The reason why at high revs this is less of an issue is because the engine is pushing exhaust gases out at a much higher rate. In the water example above that would be equivalent to turning up the power of water being pushed through the hose. In that case a large diameter hose is less of an issue, but a low water power the velocity slows and it becomes problematic.

This is why Ferrari and a few others have variable exhaust so at low rpm's the exhaust is switched to a smaller diameter to keep velocity high. At high rpm's the exhaust is switched to a larger diameter to allow the increase of exhaust gases to escape but also keep the velocity high.

These variable systems are expensive so if you are going with a custom exhaust a middle ground is ideal. If you are building a track car a larger diameter straight pipe type would be good since you spend most of the time at high rpm's. For a higher performing DD you still want some low end torque so a larger than stock pipe that is still small enough to create a high velocity at lower rpm's is ideal.

I'm sure other's have varying opinions on this but the above is what I've come to conclude after reading through various experienced individuals opinions.

[jmanous]

Variable diameter? Wow... this is probably more expensive than a new yaris...

[Redbat01]

I would not worry about the difference between 2.25 and 2.5 inch diameter pipes if the engine is otherwise stock. A mandrel-bent 2.25 inch diameter pipe should flow just fine for anything up to 150 horsepower, maybe more. There are charts on the internet, based on scientific formulas, that deal with this issue.

The decrease in restriction associated with a 2.5 inch diameter pipe is negligible at this horsepower range. In other words, you'd accomplish nothing but hanging more metal underneath your car. Now, if you're running a twin-turbo 200 horsepower monster motor in your Yaris, that's another story!

[tmontague]

I'm also putting the stock resonator back on when I get my 2.25" pipe installed. Due to loosing the dirty sound I don't want to have to deal with the potential rasp I hate. Plus it is a little loud as of now and I'm thinking it'll get annoying in a couple months.

The stock resonator is straight through and won't restrict and with the larger pipes plus aftermarket turbo muffler the noise should still be loud enough minus the potential rasp.

[tmontague]

ad my Yaris up on ramps today to install my DIY splitter. Took a look at the exhaust. All welds are very good, bends are crushed bends not mandrel. They don't have the waves in the bends but they are still crush bent.

I am going to go down to 2.25" this Tuesday but I am stuck between a couple options:

1.Just simply swap out 2.5" to 2.25", I'm worried about reducing the dirtiness of the sound and it turning into a clean raspy sound which I don't want

2. Switching the 2.5" pipe to 2.25" and add the resonator back in (not the 2nd cat). This will reduce the potential raspiness but how much sound will I lose?

I really like the sounds now (I'll post sounds clips soon) but the mechanic stated that with the smaller pipes it won't quiet down but it will clean the sound up a bit. The sound is fairly loud and at the limit of my tolerance, but it has a nice burble to it. If it has any more rasp to it than I wouldn't like it. That is what my worry is with not adding the resonator back in.

Anyone have any experience when an aftermarket muffler, larger than stock pipes and either a resonator delete or with it still installed? Curious to the differences.

[20104dr]

I have a 2010 sedan with 2nd cat out. The piping is replaced with 2 1/4" from 1st cat to a 2 1/4 inlet/ 2" outlet flowmaster muffler. No resonator. Sounds good at lower rpms but at 4500-6000 rpms sounds kinda a tinie but its a 4bahger with 106hp. I also have a header and k&n air ram. At first, I took off both cats but the sound was just insane.

[tmontague]

Thanks for the input. I'm going to see if you can use a straight through muffler or a high flow resonator instead of the stock resonator. It should give me the best of both worlds.

My exhaust has slightly increased in noise this past week so i'm going to have to put something back in to quiet it down slightly an remove the slight rasp that occasionally happens.

I'm getting it done Tuesday so i'll let you all know the difference.

I miss the torque that I had before so going to 2.25" again and adding a resonator should help increase exhaust velocity again.

[tmontague]

New exhaust being installed tomorrow. Here is a link to a short video I took of the current exhaust set up. The revs are only to about 4500rpm as the car was cold at the time. Also because it was cold you'll briefly notice the higher idle.

https://youtu.be/fdX8bSedH50

*that not my girlish laugh in the video, it's the camera woman's ;)

I love the sound, but the loss of torque isn't worth it and it gets slightly annoying when it sounds loud at light 2500rpm shifts when i'm just cruising.

Current set up:
2.5" pipe straight to turbo muffler.
Secondary cat an resonator delete.

I'll post after tomorrow with the new set up sound.

[jmanous]

So is the low-end torque loss really noticeable? If so why not going back to 2" which
is stated as the optimal for the hp range?

In a previous post it was stated that the CFM when going from 2.1/4 -> 2.1/2 change
substantial, is it possible to have similar problems with the 2.1/4?

Sounds awesome though - although might be a little loud for a DD.

[tmontague]

It's not that noticeable to the point that is affects drivability. However, because I am pretty sensitive to changes in my Yaris I have noticed it when I am driving more conservatively and trying to low shift around 2,000-2200rpm. I feel that I now need to shift as at least 2500rpm to get a decent pull. This could also be that I'm used to accelerating a bit harder the past few months so when I do low shift I feel that it lacks torque and not necessarily due to the exhaust.

It seems to have essentially canceled out my torque gain with the header I installed. I'm going to 2.25" as I really like the high Rev gains I got from a 2.5" pipe. A 2.25" with a resonator installed back in should not cause any loss in top end just like the 2.5", but it should improve exhaust velocity and gain me back most of the torque.

I feel it should be the best of both worlds. Plus the pipes are crushed bent (not the wavy type) and the sharp bend above the axle could create a narrow restriction so I feel the 2.25" is ideal. On top of that a resonator will also help a bit with the low end.

Without a variable exhaust you have to be willing to give up a bit of one end to gain in the other. Now that being said this can be minimized by using an optimal diameter pipe and set up, but there may still be slight losses.

I'll let you know what I notice

[tmontague]

At Techtune waiting for exhaust work to be done. They had a 2.25" fin type resonator for an extra $100 but I decided to save the cash and go with the stock resonator which is a perforated type and 1.8" straight through.

The perforated type should keep the noise still some what higher but stil reducing the sharpness an raspiness. It alsoo will flow better than the fine type so it was a win/win for me.

[tmontague]

Alright, got my exhaust completed and have driven about 30km highway and about 2km city. Here is the sound clip, you can compare it to the one I posted above
https://youtu.be/Hqhis-4LDpI

So now i'm at the following:
Secondary cat delete, stock resonator is still there with 2.25" mandrel bent tubing down to an aftermarket turbo muffler.

Sound from my point of view as a driver is much much quieter. At first I was a little dissapointed with how quiet it became. No drone at any highway speed what so ever which was kind of annoying me before I changed the exhaust. As a DD it would've got annoying pretty quick.

No longer really loud at low rpm, but is still loud at high rpm. Although in the cabin it's never very loud, it's actually surprising how loud it still is outside the car but not obnoxious and not bad at low revs.

Stil has a low tone to it an most importantly my torque is back! Now when cruising @80km/h in 5th , don't have to shift down to 4th fo it to accelerate as quickly to 100km/h.

Still pulls fairly hard at high rpm, but maybe not at hard as before. I'll need more time with it to determine for sure. Seems to be getting slightly louder a I drive it, which is expected an a good thing.

Tech tune did a great job again and actually didn't charge me at all. I gave them some cash anyway for their time/parts as I know it'll pay off when ever I go back there.

I'm very happy with it, i'll likely be painting it black this weekend to help it hold up longer as it's aluminum.

Eveything is welded except for the muffler attatchment to the pipe after it comes over the axle to themuffler. This makes it easy to remove t paint. Just unbolt the exhaust donut gasket after the header, unbolt the uclamp that attaches it to the muffler and drop the exhaust.

I'll update with any tone changes and further performance changes. All in all very pleased with the exhaust and happy to deal with the shop I chose to go with.

[invader166]

Awesome feedback on this thread!! :thumbup: Thanks tmontague!!

Knowing all this, I've personally decided that my next exhaust job (once I save enough money) will be to replace the mid-section with a new Magnaflow unit.

http://m.ebay.com/itm/Magnaflow-Direct-Fit-Bolt-On-Catalytic-Converter-93213-EXCLUDES-CALIFORNIA-/131308880962?nav=SEARCH

I honestly want to just stay as legal as I can but still have a slight performance benefit. Plus, both my header and muffler are stainless so I'd like to have it all the same material.

[tmontague]

Thanks man, glad it was useful. Are you planning on taking the magnaflow to to shop and have it all welded on? That set up looks exactly the same as the stock Toyota set up, is that specifically for the Yaris?

My recommendation to anyone doing an exhaust and has some cash flow would be to purchase a magnaflow (or other known brand) SS resonator and muffler and 2.25" mandrel piping. Then take it to a good exhaust shop and have them remove the second cat and then weld it all together for you.

I was limited in my budget and i'm very pleased with the results but when the exhaust rots out down the road i'll likely go with what I just recommended.

I had a good talk with YW member "thebarber" and he mentioned the stock resonator not being restrictive. He just recommended doing a resonator back exhaust.

After measuring and comparing the stock resonator to an aftermarket one I agree. I can't say how much the 2nd cat delete does for performance but I don't doubt it helps improve the sound by removing it.

I'm a tree hugger and after lookin at the emission system in the Yaris I had no issues deleting it. I recommend it for any aftermarket exhaust system.

Other members on this forum were spot on about 2.5" being too big and losing torque. If you did a 2nd cat and resonator delete then i'd probably recommend 2" mandrel bent, unless you're boosted. I have 2.25" but the resonator is 1.8" - 2" straight through and it' crush bent piping.