I have a customers 2007 Tahoe, full bolt on cammed setup. I have it currently tuned in Maf only mode. I have already performed the cruising fuel trim tuning. I just started today making some WOT hit. AFR verified via aem wideband.
What I ran into was the PE fueling would be perfect at 12.5 one minute and thin it would go pig rich at 10s. It would also seem to not exit PE mode. I could make a hit and it would seem to hang at 11s AFR at idle etc. never would return to stoich except when cruising and the O2s brought fueling back. I had to restart truck and it was fine again till I made another WOT hit. U could cruise around with a 14.7afr all day until u made a hit.
Scanner showed commanded AFR of 10.4 while crusing and idle. WOT was commanded 8ish. This is the first ive seen something act like this. I also noticed truck throwed a p101 code once when all this was happening. Maybe a possible bad maf?
If one of u guys could look this over and help I would appreciate it. Here is a log and tune. thanks.
Mods are:
Holley sniper intake 92mm, Longtubes/ORY, BTR stg3 truck cam, Circle D 3400 stall, CAI, 25% UDP and 4.11 gears.