2000 Mitsubishi Eclipse • 160,000 miles

Hello I have a 2000 Mitsubishi eclipse rs 2.4L and I am having low idling problems. It runs good in the beginning but once it is warm just idles really low like it wants to die. I have replaced the egr valve and the vacumn solinoid, new spark plugs, new iac, new tps and new valve cover gasket. Just installed new header and exhaust system also and was thinking maybe my cat was causing it but still idles low. Cleaned the throttle body and cleaned the maf also but still no change. No check engine light on I am running out of ideas
August 10, 2012.

Check coolant temp sensor, this is not the gauge sender, it is the sensor that tells the ECU if the engine is cold and causes the mixture to increase, often if faulty cold nut still wants to run rich and this can case erratic idle.

Aug 10, 2012.
If the battery was disconected, it would need some relearn time for the idling to stabilise.

Aug 10, 2012.
Ok I will check it today let you know what happens. Thank you

Aug 10, 2012.