I have a 2001 4 cyl Camry with about 147K. I bought the car from the original owner a few weeks ago. The check engine light came on. The car idles very rough at low idle (e.g., while stopped with transmission in Drive). My mechanic changed out the EGR and another air flow valve that was apparently stuck open too much of the time, and also the engine idle air control valve. The check engine light is now off but I don’t think it was related to the rough idle because that started before the check engine light. I have seen other forums that discuss the rough idle related to fuel dampener and also weak/broken motor mounts and haven’t checked those out yet. Any other ideas, before the Camry goes back for another staycation at the shop? Thanks!
Rough idle can be any number of things, but usually new plugs and wires will help. Could be the MAP/MAF sensor needs cleaning. Dirty fuel injectors. I would start with the plugs and wires and check the coils resistance to.
Post the exact fault codes that you had and we’ll try to help you.
Checking the engine compression might also be a good idea; just to make sure the engine is mechanically sound. Otherwise, one could throw all kinds of parts at it while trying to resolve a rough running problem.
Ideally, you would be looking for 180-190 PSI per cylinder with very little variation among them.