Okay, datalogging a 94 M6 TA, only mods are cold air kit and 4.10 gears.

During a drive it does okay cold, but once warmed up it will buck hard around 1700 rpm wot. spark retard is constant at this point. I even went in and took out 5 degrees of timing and it is still pulling timing.

I reved it a few times in neutral and twice I got it to pop back into the intake.

sound like opti?

attached is a datalog after I pulled 5 degrees from 80-100 kpa 2800 to 6000 rpm ranges

http://www.lt1swap.com/datalog2.uni

 

Disconnect an O2 and see if it runs better even after the SES sets.