Lean bank codes
Thread Starter
Drifting
Joined: Apr 2004
Posts: 1,889
Likes: 0
From: ottawa ontario
Lean bank codes
Can you get lean bank codes if you delete the air pump? I have a ls6 motor in my car and recently converted to a4 so i had to reflash the pcm..Tuner also told me that he put the wrong MAF meter in the tune. Instead of 85mm one he put is the factory ls1 in the tune..Would having the wrong meter set a lean code? Thanks..Mike
Burning Brakes
Joined: Sep 2004
Posts: 1,056
Likes: 0
From: Havelock, NC ( NJ Resident )
Originally Posted by mitymikec
Can you get lean bank codes if you delete the air pump? I have a ls6 motor in my car and recently converted to a4 so i had to reflash the pcm..Tuner also told me that he put the wrong MAF meter in the tune. Instead of 85mm one he put is the factory ls1 in the tune..Would having the wrong meter set a lean code? Thanks..Mike
Instructor
Joined: Jul 2004
Posts: 110
Likes: 0
From: Newport News VA
Originally Posted by mitymikec
Tuner also told me that he put the wrong MAF meter in the tune. Instead of 85mm one he put is the factory ls1 in the tune..Would having the wrong meter set a lean code? Thanks..Mike
Instructor
Joined: Jul 2004
Posts: 110
Likes: 0
From: Newport News VA
The lean code is set because the amount of fuel needed to correct for the MAF tune is outside of its programmed limits. I'm not sure if the pcm can no longer correct for the lean condition once the code is set or not.
The tune will impact hp. At part throttle, the pcm tries to maintain stoich (14.7) air-fuel ratio. Once you enter PE (power enrichment) it will attempt to maintain a multiplier of stoich at your current rpm. If the pcm is having to add fuel at part throttle (to correct for your MAF tune, for example), it will add fuel in PE mode also. This means that you will run richer at wot than what your pcm is commanding. This will most likely negate the tuner's attempts to lean out your tune (at wot) for power.
The cure would be to have the tuner fix the problem (as the code is a direct result of the tune), or replace the 85mm MAF with a stock unit.
The tune will impact hp. At part throttle, the pcm tries to maintain stoich (14.7) air-fuel ratio. Once you enter PE (power enrichment) it will attempt to maintain a multiplier of stoich at your current rpm. If the pcm is having to add fuel at part throttle (to correct for your MAF tune, for example), it will add fuel in PE mode also. This means that you will run richer at wot than what your pcm is commanding. This will most likely negate the tuner's attempts to lean out your tune (at wot) for power.
The cure would be to have the tuner fix the problem (as the code is a direct result of the tune), or replace the 85mm MAF with a stock unit.
