Huge Gas Milage Reduction from installation of intake - Toyota Yaris Forums

YarisSedan · 10-21-2008, 01:55 AM

So my yaris sedan auto was geting about 36mpg adverage. Thats with no special driving techniques just driving normally. After installation of my weapon r intake. My mpg dropped to 29-30. I attribute this to the relocation of the maf sensor. Since how much the injectors spray is directly tied to maf readings.

The MAF sensor is relocated just a few inches away from the throttle plate and i think that even though the same amount of air may be going into the intake at the same throttle position witht he stock intake the location of the sensitive sensor may get a false reading of air when accelerating. Maybe even at a constant throttle position.

I checked this by hooking up my scanner to the computer and watching live data readings of the fuel trim. If you know a bit about cars fuel trim should always be close to zero with a little switching picked up by the oxygen sensors. My fuel trim is at about 20 percent for long term.

Which means the car is constantly dumping additional fuel leading to my reduction of fuel economy.

I am curiouse to see what happens to my fuel trim if i put my factory air box back but install a simply drop in K&N filter.

Callisto · 10-21-2008, 08:18 AM

If the problem is that the MAF is reading differently, and the ECU then makes it run rich, isn't it possible to have the ECU data changed to make it run more lean? In places at higher altitudes it is sometimes necessary to have the air/fuel mixture manually changed. I presume the same kind of thing is happening here. Talk to a mechanic and find out if this is possible. It may be an easy fix.

eco · 10-21-2008, 04:13 PM

What WR intake did you buy.

darthbauer · 10-21-2008, 04:14 PM

Quote:

Originally Posted by eco

What WR intake did you buy.

So we know not to buy it.

jk

Treyz · 10-21-2008, 04:54 PM

Hmm ... the AFE actually improved mine by a couple MPG.

As for a real brand name intake. I believe the Weapon R is the cheapest out on the Market right now (under $120 I've seen).

My AFE was $165 shipped.

eco · 10-21-2008, 05:55 PM

WR has 2 versions,I just bought one of them,so I really want to know which version you bought.

marcus · 10-21-2008, 06:06 PM

is it the secret weapon r that you have..

Smokey159 · 10-21-2008, 06:10 PM

Quote:

Originally Posted by YarisSedan

So my yaris sedan auto was geting about 36mpg adverage. Thats with no special driving techniques just driving normally. After installation of my weapon r intake. My mpg dropped to 29-30. I attribute this to the relocation of the maf sensor. Since how much the injectors spray is directly tied to maf readings.

The MAF sensor is relocated just a few inches away from the throttle plate and i think that even though the same amount of air may be going into the intake at the same throttle position witht he stock intake the location of the sensitive sensor may get a false reading of air when accelerating. Maybe even at a constant throttle position.

I checked this by hooking up my scanner to the computer and watching live data readings of the fuel trim. If you know a bit about cars fuel trim should always be close to zero with a little switching picked up by the oxygen sensors. My fuel trim is at about 20 percent for long term.

Which means the car is constantly dumping additional fuel leading to my reduction of fuel economy.

I am curiouse to see what happens to my fuel trim if i put my factory air box back but install a simply drop in K&N filter.

reset the ecu. Unplug the battery for a few minutes, hook it back up and let the car IDLE for about 5 minutes, then shut it off.

you should be good to go again.

Smokey159 · 10-21-2008, 06:11 PM

BTW, my Simota Carbon Charger ($120 shipped) gained 1.5 MPG.

YarisSedan · 10-21-2008, 07:46 PM

Quote:

Originally Posted by Smokey159

reset the ecu. Unplug the battery for a few minutes, hook it back up and let the car IDLE for about 5 minutes, then shut it off.

you should be good to go again.

I tried that already and the fuel trim went back to rich. I forget which one its chrome tube with black filter. I think any filter which relocates the maf sensor to base of the throttle assembly would have the same effect. If you look at the factory filter the maf is farthest away from it right infront of the filter. Also the tube isnt perfectly smooth to help disrupt the flow slightly.

I know they do sell performance maf sensor that can read higher flows of air for heavily modded cars but should be unessisary for our cars.

anonymous user · 10-21-2008, 09:56 PM

I have the Blitz LM SUS intake. I noticed a decrease in FE, but after letting the ecu cycle after a few starts or so, it went back to normal. Staying away from increased high rev throttling and i've never had a problem since.
You have a good point though. Depending on how far the maf is away from your T.B. makes a large difference in A/F readings.

Stargate YARlantIS · 10-21-2008, 10:23 PM

i actually gained 5mpg w/ my Fujita F5, i was getting about 26....now about 31mpg

YarisSedan · 10-22-2008, 12:39 AM

Hmmm I may have to switch to a different brand. Anyone want to buy a slightly used weapon R intake =)

eco · 10-22-2008, 09:09 PM

YarisSedan,how did you mount your intake,I cant see where the bracket and bolt with rubber stoper go.

eco · 10-22-2008, 09:09 PM

Instructions suck.

10-21-2008, 01:55 AM	#1
YarisSedan Drives: 08 Yaris Sedan Join Date: Oct 2008 Location: California - Bay Area Posts: 2,773	Huge Gas Milage Reduction from installation of intake So my yaris sedan auto was geting about 36mpg adverage. Thats with no special driving techniques just driving normally. After installation of my weapon r intake. My mpg dropped to 29-30. I attribute this to the relocation of the maf sensor. Since how much the injectors spray is directly tied to maf readings. The MAF sensor is relocated just a few inches away from the throttle plate and i think that even though the same amount of air may be going into the intake at the same throttle position witht he stock intake the location of the sensitive sensor may get a false reading of air when accelerating. Maybe even at a constant throttle position. I checked this by hooking up my scanner to the computer and watching live data readings of the fuel trim. If you know a bit about cars fuel trim should always be close to zero with a little switching picked up by the oxygen sensors. My fuel trim is at about 20 percent for long term. Which means the car is constantly dumping additional fuel leading to my reduction of fuel economy. I am curiouse to see what happens to my fuel trim if i put my factory air box back but install a simply drop in K&N filter. __________________ http://www.cardomain.com/ride/3210549

10-21-2008, 04:54 PM	#5
Treyz ~ ambient one ~ View User's Garage Drives: 2009 Bayou Yaris Liftback Join Date: Jan 2007 Location: Long Island, NY Posts: 1,046	Hmm ... the AFE actually improved mine by a couple MPG. As for a real brand name intake. I believe the Weapon R is the cheapest out on the Market right now (under $120 I've seen). My AFE was $165 shipped. __________________ AMBIENTLIFESTYLE Tri-State Sport Compact EZine ambientlifestyle.com------------ambientlifestyle.ning.com Micro Image Store - Network - Online microimageonline.com------------microimage.ning.com

10-21-2008, 09:56 PM	#11
anonymous user rarer than JDM -1 of 1! View User's Garage Drives: 07yaris Join Date: Oct 2008 Location: windward oahu Posts: 402	I have the Blitz LM SUS intake. I noticed a decrease in FE, but after letting the ecu cycle after a few starts or so, it went back to normal. Staying away from increased high rev throttling and i've never had a problem since. You have a good point though. Depending on how far the maf is away from your T.B. makes a large difference in A/F readings. Last edited by anonymous user; 10-22-2008 at 02:48 AM. Reason: corrected intake model

10-22-2008, 12:39 AM	#13
YarisSedan Drives: 08 Yaris Sedan Join Date: Oct 2008 Location: California - Bay Area Posts: 2,773	Hmmm I may have to switch to a different brand. Anyone want to buy a slightly used weapon R intake =) __________________ http://www.cardomain.com/ride/3210549

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10-21-2008, 08:18 AM	#2
Callisto Drives: '08 Hatch Join Date: Oct 2008 Location: Central PA Posts: 43	If the problem is that the MAF is reading differently, and the ECU then makes it run rich, isn't it possible to have the ECU data changed to make it run more lean? In places at higher altitudes it is sometimes necessary to have the air/fuel mixture manually changed. I presume the same kind of thing is happening here. Talk to a mechanic and find out if this is possible. It may be an easy fix.

10-21-2008, 04:13 PM	#3
eco Drives: 2007 Black Yaris sedan Join Date: Sep 2006 Location: Atlanta Posts: 884	What WR intake did you buy.

10-21-2008, 05:55 PM	#6
eco Drives: 2007 Black Yaris sedan Join Date: Sep 2006 Location: Atlanta Posts: 884	WR has 2 versions,I just bought one of them,so I really want to know which version you bought.

10-21-2008, 06:06 PM	#7
marcus toyota View User's Garage Drives: 2007 Yaris RS Blazed Join Date: Oct 2006 Location: toronto, canada Posts: 3,637	is it the secret weapon r that you have..

10-21-2008, 06:11 PM	#9
Smokey159 Drives: Yaris Liftback Join Date: Oct 2008 Location: Lexington, KY Posts: 55	BTW, my Simota Carbon Charger ($120 shipped) gained 1.5 MPG.

10-21-2008, 10:23 PM	#12
Stargate YARlantIS View User's Garage Drives: 2007 Yaris Liftback Join Date: Oct 2008 Location: Saint Petersburg, FL Posts: 351	i actually gained 5mpg w/ my Fujita F5, i was getting about 26....now about 31mpg

10-22-2008, 09:09 PM	#14
eco Drives: 2007 Black Yaris sedan Join Date: Sep 2006 Location: Atlanta Posts: 884	YarisSedan,how did you mount your intake,I cant see where the bracket and bolt with rubber stoper go.