So recently here the last month or so i have been trying to figure out why my cobalt is only making 0~5 psi. Ive scoured the forums and asked many of my cobalt owning friends for ideas and so far everything has come up dry with no changes in performance. It all sort of started after I pulled into a shop to get my transmission fluid replaced and on the way out of the building my resonator got caught on something on the floor. Resonator cracked open like a pop can and so i took it off and had it repaired. i had no issues the whole time the resonator was off of the car. After getting it back and reinstalling it my issues began. So far I have done these.

• Boost leak test at least 5 times
• Cleaned and checked BPV for damage (found no signs of wear)
• Replaced MAP sensors with gms1 to match my tune
• Replaced MAF twice
• Replaced boost control solenoid
• Replaced wastegate actuator solenoid
• Replaced wastegate

I really thought the wastegate was the issue and after 5 hours spent on the replacement I still have no change in performance. I was wondering if anyone else had experienced something like this. If so how did you fix it? The only code that eventually gets thrown is a MAF range/performance code. I really have no clue what it could be at this point in time and I'm hoping someone on here may have some ideas for me.

 

check for vac leaks around the intercooler pipes. are you running any aftermarket intercooler pipes or all OEM?