I have a 2005 cavalier with 126,00 miles on the car (76,000 on the engine). I recently changed the plugs and boots. I put it back together and it was running very rough. I checked it and removing the seized plugs cracked the head.
I took it to a mechanic who replaced the heads and gasket, fule filter, and the PCV valve, cleaned the throttle body and replaced the air filter. When he was finished it was still running rough.
The idle jumps under load from 500 to 1000 erratically, it is low on power, it stalls out, and it uses more fuel. I also notice a strong exhaust smell that wasn’t there previously. No fluid leaks are present and the compression checks fine. We replaced the ECU with one off a front end wreck and it had no effect.
I believe that is all the information I have. Codes are reading that its running lean and multiple random misfire plus a couple sensor codes I can’t remember right now. Any thoughts as to what I might be dealing with here?
Get and post all of the exact codes as Pxxxx
Unfortunatly I can’t get the codes right now as it died on me on the way home. I was going to take it to a new mechanic and now it’s at the shop nearest to where it died. They will look at it tomorrow though we ruled out the fuel pump.