If these people are HPTuned, then they should log the car and check the fuel trims. Refer to the comment about the Front O2 sensor again.

When I would look at my MAF Corr vs STFT table you could see quite a few -20% cells!!! O2 = shot!!!

If the car is idling funky, stop driving it! I was seeing light throttle accel KR as well as WOT, misfires at idle or on decel etc...

 

Yeah, I'm going to mention the O2 possibility to him so they can look at that in addition to fixing whatever's now damaged.

 

Me too -20 to -25 STFT and the car would knock because of that because that damn sensor is telling the ECM to pull out way too much gasoline.

 

Yeah, I've recorded spikes up to +- 25STFT and then it'll do a reducing sine wave looking thing as it gets back on track. Only happens at low throttle for some reason. When near or in boost, it sticks to 14.7 or the WOT AFR like glue.

Ordered the O2... we'll see what happens.