The motor in this truck is all stock right out of an escalade. Has a 5.3 pcm that I put a stock tune from an escalade in. If I remember correctly the only changes that were made compared to stock were shift pressures and torque management. The first day I flashed the tune into the vehicle it ran great. No issues. Now when the engine has a load on it it seems to just randomly pull timing all the way down to 6* at times and runs like garbage. I improved on this by changing the timing table where it starts to taper off (towards negative numbers) in the higher cylinder mass cells to a flat number. Even after doing this it still pulls timing.
I used the scanner to fix timing to 17* and see what it did at one point. When I did that the timing stayed constant and the truck seemed to run better than before, but still seems to pop and miss (no misfires scanned) at WOT. Any tips on where to start looking to take care of this? I'll attach the tune... I know it's a pain to look through an entire tune to find a problem, but if someone has an idea and can check it out it would be appreciated.