Fuel Trim varience

[XP800R]

Predator U7194 V-9T18C
2010 GMC 6.2 NHT

I just updated to the new version from the version 15. In both cases I have noticed up to 5 percent difference in fuel trim numbers from left to right. I'm now at plus 1 and neg 4 with the slope at -2. Is this common to have that much difference between banks? I have not tried WOT to see how this version impacts shifiting but will tonight. It would have been nice if you could have modified shifting of the 6 speed at more levels than just WOT. Out of curiosity how did you manage that without getting into the TCM?

Thanks.

[mikel]

possible exhaust leak?

[XP800R]

Not sure on an exhaust leak. There is no sound or indication of one. Fuel tirm stock (new) with 250 miles or less when checked last March were that much apart... Is there any concern or just run it so it averages between 0 and -2?

Well, I have to give you credit on the shifting improvement.... On the way home tonight I did a WOT throttle run and the 1-2, 2-3 are almost violant.... Wow what a difference. On the negative side I felt this tune was a bit mushy or less crisp when driving 60 to 70 and slightly accelerating. Maybe that will go away with some miles? I also got a service traction and stability control light at about 50 miles from tune install. I shut it off when I got home and it cleared so maybe all is good? Thoughts on that?

Thanks!

[XP800R]

TTT

[XP800R]

Hey Mike, Just looking for your opinion on running 0 and -5 for trim.... Actually, what impact does running greater than a fuel trim average of -2 hurt... Its not like I can bring my new truck in for warranty work and state the fuel tirm is not right so there must be a problem...

Thanks.

[XP800R]

To reword it: My slope is at -2 at I have -.56 left bank and -5.78 right bank.... Any long term issues...... And yes, it runs very hard at WOT! Ican't complain!

[06MonteSS]

I would check for air leaks somewhere man....

they shouldn't be that far apart....

[XP800R]

Thanks. I checked everything and could not locate any type of leak. I'm not sure how I could even bring it in for the dealer to check out as they would wonder how I learned of the fuel trim varience. The truck has about 8500 miles on it now and it has stayed the same since I installed the tune at about 500 miles....

What are the long term impacts of running say a -5 on one side? Or how does a 5% difference between sides impact performance?

Thanks.