Hi folks,
I'm looking for some help!(as everyone is!)
I have a 01 Grand Prix. When I got the car, it would barely run at more than an idle. I did some checking and determined that the catalytic converter was plugged. I replaced it and most of the exhaust. Problem solved. The next issue was random RPM spikes, in park, or while driving (very dangerous!). I found this problem to be the idle air control valve. Replaced and all is well now with the engine. My next issue is the one I'd appreciate some input on. The car will not shift into fourth. The torque converter will not lock up either. This of course results in poor fuel economy since it does 3400 rpm at 120km/hr. There are no codes in the computer. I am suspecting a stuck 3-4 shift solenoid. I would like to know if anyone has encountered a similar issue and what the cure was. Is there possibly a problem with something on the exterior of the trans(shifter position, wiring etc) that I can check before I dig into the solenoids? I believe that a wiring issue would throw a code, is this so? The shift indicator is fine.
I thank you and appreciate your help!