88 Bonneville LE
Engine code c
135,000 miles
I started when I replaced the thermostat. When I put it all back together it was running rough and louder than usual. My dad drove it down the road and came back and said that cat. conveter got really hot. So I cut it off. Still didnt run right. Hasnt run since then. Run for a few seconds and shuts off,backfires, and pops ad burps like mad. Please help I have to drive a granny car (85 Chevy Caprice) and I cant take it much longe. Help bring my Bonneville back

What I think is wrong
1.Timing is off
2.ECM is screwed up
3.Some sensor is throwning off eveything

Oh yea if anyone in Michigan ha a 87-91 for sale tell me

Do you have a service engine soon light?

Did you mess with any of the sensors in the vicinity of the thermostat?

Use the procedure in Techinfo to pull the codes from the ECM.

If it started when you replaced the thermostat, first check everything around it - wires to MAF, coolant sensor, IAC and all the vaccuum lines - the plastic tower where four vaccuum lines tee off on top of the manifold is prone to cracking.

Anyone know of a source for repacements of that four way tee ? I could use several.

Ok since ive had the car its had a code 34 (maf sensor) i replaced and the code still wouldnt go away to i just unpluged and the car ran fine so i never bothered with it but its never put any codes out. Also how much are we talking if i replace my Ecm and how do i Go about it

Still sounds like a bad MAF sensor, especially if you unplugged it and it ran fine. Has your throttle body had anything taken out of it, or is there anything different with your air intake?

Where did you get the MAF sensor?