Hey Scotty my Brother has a 2003 Mitsubishi Eclipse and lately it been idling inconsistently between 900 Rpm and will at times drop and idle at 500 rpm. Recently it had a vacuum leak which solved the issue but was also told it may be leaking for the diaphragm of the car. What do you think the issue is?
Check all your intake pipes, vacuum hoses, and throttle body for any air leaks (basically any air leak past the MAF sensor). You may need to clean your throttle body. I would suggest taking a look at the short-term and long-term fuel trims at idle and reporting them back to us. Should be between -10% and 10%. If not, your O2 sensor is probably failing and needs to be replaced (assuming the fuel system and air injection system are good). As I like to say...get to diagnosing!
