Running Lean
Thread Starter
Former Vendor
Joined: Dec 2001
Posts: 5,261
Likes: 1
From: The Presidential Suite Elite Street, MD
St. Jude Donor '08-'09-'10
Running Lean
My check engine light keeps coming on every other time I drive the car it seems. I am using the Predator Programmer and it is telling me that it is running lean banks 1 & 2. I have the Halltech T1-C and a 160 thermostat and have re-programmed my fans to come on earlier. Does anyone know why this maybe happening so frequently. Also I need to have the fuel sending unit replaced, could this be the problem. Thanks in advance for any help you guys/gals can provide.
Le Mans Master
Joined: Apr 1999
Posts: 7,820
Likes: 0
From: Burlington ON
Cruise-In I, II, III, IV & V Veteran
CI-I & II Auto-X Champ
Re: Running Lean (Z06Joe)
Your Fuel Trims are maxed out, meaning they are doing all they are capable of in trying to fix your part throttle lean condition.
An adjustment to your fuel injector or MAF table with LS1Edit is necessary to richen things up so that this code will not pop up anymore.
The thing is, when your Fuel Trims max out like this, you are actually running VERY rich at full throttle because the PCM is dumping in all the extra fuel that the trims tell it, plus adding in the fuel from the wide open throttle table.
An adjustment to your fuel injector or MAF table with LS1Edit is necessary to richen things up so that this code will not pop up anymore.
The thing is, when your Fuel Trims max out like this, you are actually running VERY rich at full throttle because the PCM is dumping in all the extra fuel that the trims tell it, plus adding in the fuel from the wide open throttle table.
Pro
Joined: Apr 2002
Posts: 726
Likes: 2
From: Denver CO
Re: Running Lean (Z06Joe)
Be sure to check for air leaks (vacuum leaks) on the "intake", especially behind the MAF. This could introduce enough air to lean you out beyond the trims as Matt mentioned. Since the long term trims can move @ 23%, it's hard to believe that the mods you have would have leaned it out that much. Maybe with headers and cat back in addition to that, but with only an aftermarket intake???? Doesn't sound right. Oh yeah, you might check your fuel pressure. If low, it could contribute to the problem.
Good luck! and let us know what you discover.
[Modified by TopCat, 9:35 AM 10/10/2003]
[Modified by TopCat, 9:37 AM 10/10/2003]
Good luck! and let us know what you discover.
[Modified by TopCat, 9:35 AM 10/10/2003]
[Modified by TopCat, 9:37 AM 10/10/2003]
Le Mans Master
Joined: Apr 1999
Posts: 7,820
Likes: 0
From: Burlington ON
Cruise-In I, II, III, IV & V Veteran
CI-I & II Auto-X Champ
Re: Running Lean (TopCat)
It isnt uncommon for a Z06 with air intake, exhaust and header mods to experience this code... And to top if off, who knows what that Predator Programmer did to the A/F's.
