Well I installed my third and last Nelson tune, tonight and the truck still is lean the top end. I KNOW it isn't the Tune, Allen has when far past the point of good customer service. I've check for vacuum leaks, and my fuel pressure goes up to 60 PSI at high idle, what else is there to check see sig, for all mods.
P.S. If ANYONE is thinking of getting a tune or tuner, I would recommend Nelson.

 

have you had the injectors cleaned latley?? or the throttle body? changed plugs,wires? cleaned the air filter? wipe out the inside of intake tube? cleaned maf? fuel filter? just a few of the problems i have ran into with the trucks running lean on topend.

 

oh yeah what is your maf reading right before you shift into the next gear??

 

How lean is lean? where is your O2 senser located? What brand/kind is it?

 

New fuel pump, filters and 44 injectors. trims go to 25% and it stays at 15.1 on my Dyno jet wide band. Stock O2 sensors.

 

disconnect your maf and then plug it back in after you disconnect the batt.

 

Did you change to an 02 PCM yet? I had all kind of problems with the 00 PCM. Running lean and false knock.

 

Ya I got a 02 from Nelson. I'll try the MAF plug in thing v8.

 

How much gas in the tank? Because if i do WOT runs with less than a 1/4 tank mine will go lean.

 

It is lean even with the tank full. I just got done doing a smoke test to check for vacuum leaks and came up with nothing. What else could it be??????