Because of the release of the 2007 truck line recently I have tuned several 2006 trucks & suv's . (pick-ups-yukons-denalis-tahoes---etc.)
The problem i am having is that after tuning them and then driving them to log various pids, I can't seem to get the vehicle to operate out of closed loop. The AFR's are always stuck on 14.63 at WOT---the 02 voltages still oscillate at WOT
and power enrichment mode is never activated---no matter what I've tried to do or change---And i've tried tons on things---I've changed all the normal things--took out all the delays--set the AFR @ RPM at 12.70--set the tps activation at 58% etc etc.

Do these vehicles ever operate in an open loop type status ( OL-DRI) to activate power enrichment???---Or do they always just run in a closed loop mode??----It seems that a few 06's have taken the changes and allowed me to change PE---but lately almost all won't----Anybody know ? Am I doing something wrong ? or is this the way they operate now??-- THKS Tom