1996 Mercury Villager Q&A

1996 Mercury Villager Question: rpms erredic when warm

my villager runs fine when cold. when it warms up the rpms jumps up and down and i pulled over i saw the catalytic converter was red hot and it was running rough what can the problem be? -
Answer 1
Sounds like the engine is misfiring. Get the diagnostic trouble codes to find out what is triggering the misfire. Read this for info on what can cause this: http://repairpal.com/OBD-Code-P0300 -