Rough idle
 

I have noticed recently when I'm coming to a stop light and have to sit there for a few minutes my monte idles kinda rough, it's "jumpy" and seems like I will stall any moment. I have looked around and saw a few suggestions. I would like to know where to start looking first?

I saw a post stating that a bad catalytic converter could cause this problem? In the past few days I feel as my car has gotten louder, could this be my problem? The previous owner replaced the mufflers and part of the exhaust but I am not sure if the converter was replaced as well.


Thanks in advance for any advice!

Might also be a dirty throttle body impeding airflow at idle. It isn't much work to get to it. 3 bolt for the throttle body and removing the intake tubing to it. Costs one brillow pad some shop towels, a new gasket, and a can or two of spray acetone (break cleaner or throttle body cleaner) so about $20 or less and 30 minutes of your time.

Worth trying before you go to the cat