I have a 2004 coupe automatic, every day driver. I just had 100,000 mile maintanance done at dealership. Now this idle problem. It is ready to die at red lights. Sluggish in the 1500 RPM area. Highway driving is ok. I did not have an issue before the service. The service guy cannot find anything, said it was fine. Well, it's not fine.
What should I tell them to check?
Could they have gapped the plugs incorrectly?
I'm not mechanically inclined.
Janice

 

It sounds like the crankshaft position sensor. Theres lots of threads here that talk about it as it is a common problem. Another quick thing you should do is make sure that your intake cover is on properly. It happened to me one time where I put it back on, but not all the way covering the hole and I started getting those symptoms. after I put it back on properly, the issues went away.

 

Sorry your having problems, one thing I would check is a vacuum leak. I heard you take a propane tank to the rear or anywhere intake vacuum air is and let it flow without lighting it while the engine is running. If there is a vac leak, the engine will race with the propane being sucked in. Thats what I would check!

 

Thank's so these are the fixes I've read so far:
Mass air sensor probe, dirty fuel filter, EGR Valve, Throttle Body Cleaner, Crank shaft position sensor, intake cover.
Lot's to look into! Right?

 

You need a Tune-UP.

 

Mine is doing the same thing and also throwin the po171 and po175 codes (lean) mine ran rough for a bit (weeks) before throwin the codes....Im doing my fuel filter again this weekend last did it at 50k...also gonna clean o2 sensors and maf sensor. 108K miles

 

Janice, What exactly did the 100K mile maintenance include??

You mention gapping of S.P........Did they replace the spark plugs......if so, they may have mixed up S.P. wires when re-installing??
Sounds like you may have a misfire condition.

 

When I had the maintanance done, they replaced the CPS because I had intermittant starting issues. Maybe it is a defective sensor. I have to take her back in to service. Im going to mention the codes since I've got none.

 

I would also have them check for a vacuum leak and that the engine cover is on CORRECTLY and sealing...

The simple things usually confuse them......