01 gagt hesitation no codes

[1bad_z28]

I just purchased an 01 grand am gt. It i really low on power and hesitates from 2-3k rpm. The vehicle has a new fuel pump, and it has had a recent tune up. The vehicle is not throwing any codes at all. This is what really stumps me.

I found two GM TSB's relating to this problem, and each say that the PCM needs to be reprogrammed. The two TSB's are listed below.

#02-06-04-009 Hesitation or Stumble on Throttle Application After Cold Start (Reprogram PCM) - (Feb 21, 2002)
#99-06-04-050 Hesitation Or Lack Of Power On Acceleration (Reprogram PCM) - (Oct 21, 1999)

Has anyone experienced a similar problem or found any solutions? Any advice would be appreciated.

Thanks,
Ryan

[1bad_z28]

As an update i replaced the fuel filter and fuel pressure regulator. I tested the fuel pressure before/after both with the car on/off and it was about 50psi. Another symptom is that the car wont rev past 4800rpm in gear as you can see in the log file.

I finally ran a scan with the VCM Scanner. The VCM Scanner is showing misfires and tons of knock, but yet the I dont have a single stored code in the system. I am completely at a loss here, I have no idea. Attached is the file, hopefully someone here can chime in.

[MMGT1]

I know this is a bit old....Can you also post the tune you have on it?