Multiple fault codes but no CEL

[Neinris]

Hi everyone! I've noticed a slight misfire about a few months ago, but I've been ignoring it since it wasn't throwing a CEL. I finally hooked up an ODBII scanner and low and behold I have quite a few fault codes popup. Now She's got my attention. Wondering if anyone has seen this, or hoping that someone could help me narrow it down, or quite possibly all the sensors are bad! :frown:

I'm gonna list all of them in order that the scanner displayed them they all start with "P":
0300-random misfire
0171-too lean
0172-too rich
0037-HO2S heater control circuit low
0038-HO2S heater control circuit high
0100-mass airflow circuit
0101-mass airflow circuit range/performance
0102-mass airflow circuit low input
0103-mass airflow circuit high input
011B-engine coolant temp/intake air temp correction
0137-O2 circuit low voltage
0141-O2 heater circuit
0335-crankshaft position sensor a circuit
0420-catalyst system below threshold
043P-evaporative emission system leak detection reference orifice low flow
043F-evaporative emission system leak detection reference orifice high flow

Are they all just related to the misfire? I know a bad crankshaft position sensor may throw a misfire, I might start there.

[ex-x-fire]

Clear and go after the first one that comes back.

[Neinris]

Clear and go after the first one that comes back.

Thanks for the reply.

I cleared all I thought, and everything came back. I might have a vacuum leak. will check tomorrow, and will keep you all posted.

[Neinris]

Like the title said there’s some new faults after I did some things, but some remained. P0300, 0171, 0172, 0100, 0101, 0102, 0103, 011B, 0136, 0137, 0138, 0139, 0141, 0335, 0420, and 043E. Alright, so I checked for vacuum leaks by doing the carb cleaner trick, be careful with this as this fluid is flammable, but no vacuum leak detected even though I have the hose from the intake manifold to the evap purge valve deteriorated. See picture below. I replaced the evap purge valve, I think the old one is caked with carbon, meaning the canister is failing. Sigh, got to change that I guess. I bought the wrong sensor, cam position sensor, when I meant to buy the crank position sensor. I’d have to go return it, and don’t have time to mess with that right now. I’ll buy the O2 sensor while I’m at it and hope to install next weekend.

[Neinris]

Alright, so I've done some research and I think I've narrowed down the culprits.
Just dropped about $220 US on both O2 sensors and MAF sensor. All Denso parts from RockAuto, I consider it cheap since they're all OEM. I didn't want to just replace one O2 sensor, since they work in tandem and I'm sure the other one is probably going to fail soon. She has over 140k miles, and I hope to put another 100K or so.
Also, I have an exhaust leak from my axle back, I've jerry rigged the muffler a couple of months ago, but it's not holding up. I convince my wife that I can't pass emissions with a leaky exhaust, so she let me drop about $300, including shipping, on a new muffler, I didn't tell that it's a Tanabe Medallion Touring-S exhaust. :biggrin: Hope they all get here before the weekend. I'll scower the junkyard this weekend or the next for an evap canister, that's just too expensive to buy brand new.

Here's the link to the site where I bought the muffler, it's the cheapest I've found: https://sparktecmotorsports.com/i-30621836-revel-medallion-touring-s-exhaust-system-2007-2011-toyota-yaris-hatchback.html?v=1

[06YarisRS]

Alright, so I've done some research and I think I've narrowed down the culprits.
Just dropped about $220 US on both O2 sensors and MAF sensor. All Denso parts from RockAuto, I consider it cheap since they're all OEM. I didn't want to just replace one O2 sensor, since they work in tandem and I'm sure the other one is probably going to fail soon. She has over 140k miles, and I hope to put another 100K or so.
Also, I have an exhaust leak from my axle back, I've jerry rigged the muffler a couple of months ago, but it's not holding up. I convince my wife that I can't pass emissions with a leaky exhaust, so she let me drop about $300, including shipping, on a new muffler, I didn't tell that it's a Tanabe Medallion Touring-S exhaust. :biggrin: Hope they all get here before the weekend. I'll scower the junkyard this weekend or the next for an evap canister, that's just too expensive to buy brand new.

Here's the link to the site where I bought the muffler, it's the cheapest I've found: https://sparktecmotorsports.com/i-30621836-revel-medallion-touring-s-exhaust-system-2007-2011-toyota-yaris-hatchback.html?v=1

Congrats on the Tanabe. Beautiful piece of hardware. I looked at them before I bought my Megan. I only bought the Megan because I found one on eBay for $100.00. The Megan narrowed to 1.14" where the tip attached to the muffler body - far too restrictive for my 2ZR turbo, but probably perfect for a stock car. Any chance you could do me a favour and measure the diameter at the tip and muffler body connection? Tanabe says 50mm ID, but I wonder if that's all the way through. Right now I have a Walker turbo muffler on there and it's only aluminized. Down the road, I'd like a nice, mandrel bent, SS solution.

[Neinris]

Congrats on the Tanabe. Beautiful piece of hardware. I looked at them before I bought my Megan. I only bought the Megan because I found one on eBay for $100.00. The Megan narrowed to 1.14" where the tip attached to the muffler body - far too restrictive for my 2ZR turbo, but probably perfect for a stock car. Any chance you could do me a favour and measure the diameter at the tip and muffler body connection? Tanabe says 50mm ID, but I wonder if that's all the way through. Right now I have a Walker turbo muffler on there and it's only aluminized. Down the road, I'd like a nice, mandrel bent, SS solution.

Sure thing! The diagram shows it narrows at the neck of the tip though. But I'll take measurements anyway and picture of the inside of the neck. I'm hoping it's good enough for NA 2ZR when I finally get mine in.
I'm supposed to get all the parts on Friday. Looks like I have a small project to do this weekend. :biggrin:

[06YarisRS]

Sure thing! The diagram shows it narrows at the neck of the tip though. But I'll take measurements anyway and picture of the inside of the neck. I'm hoping it's good enough for NA 2ZR when I finally get mine in.
I'm supposed to get all the parts on Friday. Looks like I have a small project to do this weekend. :biggrin:

All the parts on Friday for your o2 sensor/MAF work, or for your 2ZR swap?

Thanks for being willing to take the measurements. I bet it will come in handy for more folks considering the Tanabe.

Cheers,

Adam

[Neinris]

All the parts on Friday for your o2 sensor/MAF work, or for your 2ZR swap?

Thanks for being willing to take the measurements. I bet it will come in handy for more folks considering the Tanabe.

Cheers,

Adam

The O2 sensors, MAF, and muffler...

The 2ZR swap will have to wait when I move back to Maryland, maybe this summer.
I'm glad to take measurements, I'd like to contribute as much as I can and give back to the community, which has given me a lot as far as knowledge and ideas.

[Neinris]

Ok, so I've replaced both my O2 sensors, and MAF sensor, but yet I still have faults... Sigh... I did discover when I was replacing the O2 sensor in the header that I have an exhaust leak between the header and midpipe flange. I replaced the doughnut gasket and the downstream O2 sensor when I had my car on the lift this morning. This story will roll into my other post.
Anyway, I forgot to bring the ODB II reader, so I checked for faults again when I got home, and the following faults popped up:

P0300, 0171, 0172, 0100, 101, 102, 103, 011B, 0335, 0420, 043E, 043F, 0441, 0451, 0455, 0456

When I deleted them the fault changed to the original ones:

P0300, 0171, 0172, 0037, 0038, 0100, 0101, 0102, 0103, 011B, 0136, 0137, 0141, 0335, 0420, 043E

I don't have a CEL, and the engine hesitation seems to have went away when I've fixed the exhaust leak. Not sure if the ODB II reader I'm using is just not deleting my faults completely. It's a cheapo $50 reader.

Not sure where to go next, maybe fuel and spark? I have been thinking of upgrading my fuel pump, it's probably getting tired, since another 08 Yaris owner that I met at a car meet had to get his replaced just recently. The upgrade will be covered in another thread.

Well, stay tuned I guess if you're interested to see if I'm even able to get rid of my fault codes.

[ex-x-fire]

I'd be checking ground to the ecm.

[Neinris]

I'd be checking ground to the ecm.

Hmmm... I did install a cruise control years ago, I might remove the wire that goes to the ECU really quick. Thanks for the tip.

[remcafee]

take a deep breath and keep it simple stupid, start logically first check you battery and ecu connections and make sure theyre clean and tight and free from corrosion, check for signs of any rodent tracks that they mightbe nibbling on somewires, thats an awful lot of codes at the same time buddy its gotta be somethingbig and simple that youre missing

[Neinris]

take a deep breath and keep it simple stupid, start logically first check you battery and ecu connections and make sure theyre clean and tight and free from corrosion, check for signs of any rodent tracks that they mightbe nibbling on somewires, thats an awful lot of codes at the same time buddy its gotta be somethingbig and simple that youre missing

Thanks! I'll check the ECU connections and battery terminals tomorrow after work. I didn't see any traces of rodent tracks or droppings when I replaced the upstream O2 sensor, and when I had her on the lift when I was replacing the doughnut gasket between the header and midpipe, and also replacing the downstream O2 sensor, so I don't think it's that. And I don't see much rodents roaming around where I live here in San Diego.
I've removed the negative side of the battery multiple times, but not the positive, I didn't really peek behind the red plastic cover. I don't have a CEL and she runs great now after I've made those repairs, probably didn't need to replace the sensors, but definitely the exhaust gaskets. You wouldn't even know that there's something wrong unless you plug the ODBII scanner, which is just something that bothers me.

As previously mentioned in the thread, I went with all Denso parts for the O2 sensors and MAF sensor, from RockAuto, hopefully they're not fake, $220 is not cheap but considering they're Densos, kind of cheap. I don't mind spending that much as long it gets fixed at this point.

I'll keep you all posted.

[myfirstyota]

im also using the denso downstream o2 from rock auto. No issues yet and 100,000km on it now.

[Neinris]

im also using the denso downstream o2 from rock auto. No issues yet and 100,000km on it now.

That’s awesome! Good to know.
So I’ve cleaned the battery terminals and the cables. I’ve also removed and checked the ECU connectors, that was clean as a whistle. The rubber seals really do a great job, I probably did more harm than good looking at them.
It was raining this morning and my serpentine belt slipped for a bit, and I noticed that my radios backlight went out, even though it was station was still on. I did a battery test and it passed. So I really don’t know at this point.
I mentioned earlier in the thread that I bought the throttle position sensor, I ended up returning it, since the ODBII reader is able to read the RPM. Anyone think that it could still be faulty?

[remcafee]

if i were you i would have a dealership diagnosis report and see what they say, sounds to be something very problematic for a diyer without the proper scan tools and equipment to analyze data.

[Neinris]

if i were you i would have a dealership diagnosis report and see what they say, sounds to be something very problematic for a diyer without the proper scan tools and equipment to analyze data.

Thanks! Yeah it’s exhausting, I’ll probably do just that. I was just hoping if maybe some here has seen all these faults at once. I guess depending on the issue they find, I’ll just fix it myself if I can. :biggrin:

I’ll keep you all posted.

[Neinris]

Went to a pick and pull today, and found a 2007 Yaris Sedan. I pulled the evap canister and pump, but I still have the P043E & F faults. Not sure if the canister and pump I got are also faulty. I can’t put my old one, cause the mounting bolts broke in the housing. Sigh... there’s a 30 day warrantee for the canister and pump that I pulled, I might go back and exchange it for another that’s newer model. The other faults I think is an electrical issue. I wonder where their common points are? I think I’m giving up and gonna ask a pro for help.

[remcafee]

sounds like a big mess, if you have skills to drill, you need to drill out the broken bolts and get the correct tap to clean the threads, i belive theyre 6x1.00, use a little anti seize when putting new bolts in, you also need to get a shop or the dealer to smoke test it for evap leaks, thats the easiest thing to do and go from there

[Neinris]

sounds like a big mess, if you have skills to drill, you need to drill out the broken bolts and get the correct tap to clean the threads, i belive theyre 6x1.00, use a little anti seize when putting new bolts in, you also need to get a shop or the dealer to smoke test it for evap leaks, thats the easiest thing to do and go from there

I tried drilling the ones on the side with the pump, but I couldn’t get it centered cause the pump’s in the way. I didn’t want to unbolt the pump, I have a feeling they’d break too. I’ll just leave it alone.
I wouldn’t have removed the brackets from the one I pulled from the junkyard if they didn’t charge for the brackets as well. I already bought new bolts for the canister that I got from the junkyard and yes, I put anti seize, I pretty much put it on almost everything. I’ll learn to keep the bolts from the junkyard next time. One of the weld nut, that secures the canister underneath, also broke off from inside the spare tire compartment. Sigh... Luckily it’s one of the two on the driver side. I bought a replacement nut and bolt, but didn’t bother putting it in yet, as I’ll be returning the canister for a replacement. I’m going to another LKQ, 45 min away, hopefully they have a better inventory. I called in and made sure I can return the part even if it’s from another one of their site. Hopefully I find a Corolla or Matrix with rear disc brakes while I’m there. And of course an evap canister and pump that’s in better shape.
What did you mean by smoke test? The whole car’s evap system or just the canister I pulled?

[06YarisRS]

Have you put a voltmeter on your alternator? With all those codes, I'm wondering if you're having voltage delivery problems. Of course, you're not having drivability problems, so maybe not.

[remcafee]

a smoke test will determine and pin point any evap sustem leaks, what you do is pinch off your rear vent by the gas tank and put the smoke tester straight into the evap system and you will see if theres smoke coming somewhere, is your car rusty? sounds like you have a lot of rust with all the bolts that are breaking. i would give your car a wd 40 bath before touching another fastener on that thing

[Neinris]

Have you put a voltmeter on your alternator? With all those codes, I'm wondering if you're having voltage delivery problems. Of course, you're not having drivability problems, so maybe not.

Actually, I didn't... That's why I thought maybe my belt was slipping a bit. It passed the voltage test when I used the ODBII reader. I'll check right now.

[Neinris]

a smoke test will determine and pin point any evap sustem leaks, what you do is pinch off your rear vent by the gas tank and put the smoke tester straight into the evap system and you will see if theres smoke coming somewhere, is your car rusty? sounds like you have a lot of rust with all the bolts that are breaking. i would give your car a wd 40 bath before touching another fastener on that thing

The undercarriage is surprisingly not that rusty, but yes there are components that are, like the bolts that connected the midpipe to the header and axleback, and the bolts that held the evap canister. :redface:

I'll test my alternator first, like Adam said, if that's fine then I think I'm done messing with her and just head to the shop. Could it still be possible that my evap is fine and it's just faulting out because of electrical issues?

[Neinris]

Actually, I didn't... That's why I thought maybe my belt was slipping a bit. It passed the voltage test when I used the ODBII reader. I'll check right now.

Ok, so I let her warm up to idle, took the negative cable off the battery, and read the alternator to ground, and she's making +14VDC. So that's not it... :frown:

[remcafee]

off to the shops then...

[Neinris]

off to the shops then...

YUP! I grabbed a 2012 Corolla evap canister, the related faults didn't go way. So I'm done trouble shooting. I'll post once the shop finds the fix. Stay tuned! :smile:

[Neinris]

My apologies it took me forever to reply back. First thing's first, the ODB2 reader that my cousin had, which what I was using when I was back in San Diego was faulty. I ended up troubleshooting the false fault that it was showing, which lead to replacement of parts that didn't needed to be replaced and ended up causing an actual fault. When I got to Maryland, I used my friend's tablet type ODB2 reader and showed the actual fault.

Anyway, I actually fixed this issue a long time ago, back in August when I finally moved back to Maryland. It was the vapor purge solenoid under the hood that was causing the problem. I didn't think it was bad, because I already replaced it when I was chasing the problem. But apparently the one I bought from Auto Zone was intermittently bad, which I paid full price for, I don't even know how much it was, I think around $70. I bought one from eBay for $12 and voila!!! And no CEL ever since.