Engine Mechanical problem
1992 Pontiac Sunbird 6 cyl Front Wheel Drive Automatic 215000 miles
I have a 1992 Pontiac Sunbird SE. 3.1L V6 Automatic. 215 000km on car 50 000km on rebuilt engine. Recently the car was running poorly and would stall while in drive when I came to a complete stop. Then the other day while going up a hill I stepped on the gas and one of the cylinders cut out. It is badly misfiring and sounds as if it is running on 5 cylinders. When the engine is cold every minute or so it sounds like the 6th cylinder is kicking in (usually only above 2500rpms though). Also right when it started doing this the catalytic converter started glowing red. I replaced the Cat thinking it may be plugged but it made no difference.
Any help is greatly appreciated.
Update: Today I tried fuel injector cleaner thinking it was a clogged injector and it did nothing. I am about to change the EGR valve.
Update 2: After changing the EGR valve it made no difference. Also shortly before changing it the 6th cylinder stopped kicking in randomly.