Any HP tuners on here? My car came with a locked Trifecta tuned PCM. I just recently swapped in a stock replacement PCM. After installing the stock PCM, my car has a very rough idle when you first start it when it’s cold. Almost like it’s cammed. After the 1st initial warm up it’s perfectly fine and idles smooth. I didn’t have this with the Trifecta tuned PCM. Being that PCM is locked, I am unable to pull the information from it to see what they had the settings for it. So I am wondering what should I try adjusting in the PCM to help with the cold startup? I have already HP tuned the car and its running great besides the start up idle.
09 Cobalt SS/TC
HP Tuned @21psi
K&N SRI Intake
Hahn Upper IC pipe and Intercooler
Cat & Muffler Delete
Also should I just stick with 21 PSI or push it any farther? My car does not have the 3 bar sensor upgrade.