Engine Performance problem
1989 Oldsmobile 98 6 cyl Front Wheel Drive Automatic 168000 miles
The car starts fine and runs fine until it warms up and goes into closed loop mode. Then it does not die but chugs, surges, pauses, runs rough. It started out minor and now is getting worse.
What I have replaced so far:
Plugs, wires, EGR, IAC valve, Ignition control module and coils, fuel filter, O2 sensor.
About 2 years ago the dealer put in a remanfactured ECM assembly.
I cleaned the throttle body and checked for vacuum leaks and bad hoses. I checked the fuel pressure and it runs steady at 35psi (within spec).
I am suspecting a bad catalitic converter or maybe it's the Crank or Cam position sensors. What do you think?
have the same problem?
Sunday, May 31st, 2009 AT 7:38 AM