I posted a while back about CEL PO2178 (Rich at cruise/accel) for the past 2000 miles or so, and my dealer has had the vehicle for some time now trying to fix it, to the point they have replaced all hoses and even the IC. Ever since the CEL's began, my boost has not been above 10 psi and a high pitched whistle is heard (not turbo sounds, we thought it had to be a boost leak). Not to mentioned it's VERY weak.

We finally hooked up a Vehicle Recorder Device and drove around and it shows 24 psi!!!! I can assure you I'm not boosting 24 psi It is so weak that I don't even believe I'm hitting 10 psi. My question is, where does the gauge receive boost reference and where would the VDR get boost reference. Could it be my turbo is really producing 24 psi but the boost is leaking somewhere and the intake is only getting 10 psi??? That would certainly explain my rich CEL's.

On another note, we have went over the clamps time and time again and everything is tight. I'm trying to convince the dealership into pressurizing the entire charge line system from turbo to intake, but they only do what GM tells them. Does anyone actually diagnose vehicles anymore...LOL.