Hello, I have a 1995 GMC Suburban 2500 4x4 with the GM 5.7 engine. Motor / transmission was replaced approximately 52K ago and the body has 307K. Recenetly, there was an intermittent check engine light. The error code shown a bad O2 sensor. I replaced the O2 sensor as well as the MAP sensor. This cleared out the trouble code. Now, the motor tends to run rough above 1500 RPM and although the motor will start up an idel fine, it tends to die when you put the transmission into drive or reverse. What could be the cause of this? These problems were not present prior to changing the two sensors. Thank you.
All right first only use OEM sensors do not use cheap Chinese knockoffs or other cheap parts. The problem occurs after changing the parts odds are you got bad parts.
Thank you, The parts were through NAPA Auto Parts...the O2 sensor was an NGK brand and the MAP sensor was a "NAPA Gold" brand. ...neither one was cheap at the register, ha !