Last night I put in the new SARD FPR to drop the idle fuel pressure for the 370 injectors. But this morning I started driving and everything was fine for the first mile. Then I hit boost and threw a CEL, and the car started acting up. Basically at light throttle, the tranny won't shift (yes it is an auto). If I get on it a little more, it will shift at 6K rpm, but at full line pressure. If I floor it, the tranny will shift at 5K and flare up because for some stupid reason, it's not sending full line pressure at full throttle.

I'm throwing the 0504 code which is the TCM. I've had this problem before a while back when I first put in the emanage, we tapped the wrong wire and accidentally tapped on for the tranny. But that was fixed and the car was fine. So I know what causes this. Problem is, we checked and that wire is still fine. So I'm not sure where else to check.

It's not the tranny itself, it's not slipping, it's just this weird not shifting issue. And if it's not the TCM wire near the ECU, I'm not sure what else it could be since none of the other wires for the TCM seem to be an issue. I really don't want to have to pull all the wires and test them individually so any insight would be appreciated.