Chrysler Repair: rough idle with no code

Question
I have a 1996 Sebring LSI 2.6L 83,ooo miles. Last week I took a 300 mile trip, she ran well. I refueled about 30 miles from home and now I have a rough idle situation. Sometimes she will stall after coming to a stop, other times will idle rough for a few seconds then return to a normal idle and other times will continue to idle rough with a slight surge. There is no check engine light and I checked for codes using the ignition switch method and found only a 55 code indicating end of test. About 3 years ago I replaced the water pump, timing belt and associated bearings.
Probably not related to the problem but the overdrive light in the dash is out. Could you advise how to trouble shoot and replace the overdrive light.
Also maybe worth mentioning, occasionally after decelerating, not to a complete stop, the throttle will stick slightly at idle.
Any ideas would be greatly appreciated.

Fred

Answer
Hi Fred,
Just for clarity I assume this is the engine 2.5L?
The most likely reason for a rough idle is that the exhaust gas recirculation valve (egr) is sticking slightly ajar rather than closing to a dead stop. The first thing to try is lubricating the valve stem with a solvent such as WD-40 and then exercising the stem back and forth via the slot in the stem into which you insert the tip of a screwdriver. The egr is located in a small diameter exhaust pipe that branches off the front exhaust manifold. It has a round top with a vacuum hose, and between that and the valve body attached to the pipe is a flange which partially conceals the stem. So find the egr, the flange area, and the stem, then the slot of the stem. Then spray the WD-40 on the stem where it enters the valve body, then exercise the stem to be sure that the internal spring action returns it to a dead closed stop position.
Lets deal with the overdrive light in a follow-up question after the idle problem is resolved. The throttle is operated by a cable from the pedal to the throttle body on the engine so look over that cable for possible binding or need of lubrication, starting at the throttle body end, and check the pedal end for dirt/debris or tangle with the carpet.
Roland