Hey guys, what would make my car idle rough every once in a while. Sometimes it will run as smooth as it can get, and sometimes it is shaking pretty good. I changed my opti about a year ago, I have replaced my IAT sensor, cleaned my TB, cleaned my IAC valve, and have cleaned off my MAF. None of these things fixed it at all. Any ideas. Would bad plugs or a bad wire do this. I cant see why it only does it sometimes.

 

me too, i think mine is the opti or o2's.

but who really knows, i am just gonna start raping things till i find it...

 

I had sorta the same symptoms as you, but had a check engine light too. I got my ScanMaster in the mail the other day, hooked it up, and saw my O2's are shot.

ScanMaster = coolest toy ever.

 

intermittent problem, more likely sensor, and o2 sensor gives lights, and causes u to change from closed to open loop if its bad enough.

 

I have had no lights though. Its just sometimes the car runs rough at idle but with even the lightest throttle it goes away. I cant figure this one out.

 

do u have an auto or manual? if its a manual, then it iwll feel rough even in gear when you are diving it.

if its an auto, it iwll feel rough at idle, and and speeds above 50mph (OD) when the torque converter locks up

 

I have an auto trans. The problem never shows up anywhere through the power band or any other time except idle. Its just occasional rough idle when I am at lights. Dont know what else to tell ya. I just thought maybe someone has had this happen and would know what it would be.