Okay guys, I've searched the board for cars with this problem I have, but there hasn't been any posts that have given me a solution.

The car idles smooth when cold, gets rough when it warms up.
If I turn the car off, wait for 5 seconds, then restart, the car will idle smooth again for about 2 minutes., then it gets lumpy again.

I have done a complete tuneup, including plugs wires etc.

I have an upcoming E-test, so I'd like to find the problem before I go.

Thanks in advance.

Scott

 

when u did a yune up did u change the O2?....what about the coolant temp sensor

 

yep, replaced the coolant sensor, did not do the o2,

do you think that's it???

I've never had the service engine light come on.

 

it could be the 02...untill the 02 sensor gets to 660 degress the car wont run off the puter, when the o2 gets hot then its goes into closed loop and the car runs off the ecm

try to pull a code out of it..

 

There are quite a few posts on this topic. There are tons of things that can be causing that. vacuum leaks, faulty injectors, faulty vapor system, leaking EGR system, AIR, etc.

Clean your IAC passages and reset the IAC first, and if that fails, I'd pick up a Helm manual and start going through the list. There's at least 12 things that come to mind for rough idle. The IAC resides on the bottom of the throttle body. You'd need to take off the throttle body, remove the IAC, and take the throttle body apart, clean it with carb cleaner, replace the gaskets and reassemble the throttle body. Plug the IAC back in, then follow the IAC reset procedure in the tech section of www.thirdgen.org.