I have a 99 stratus 2.4L that runs rough at idle. Acts like it is misfiring but throws no codes. Problem is worse with the car in gear but at times it runs fine, very intermittent. When driving you can tell its not running right, like its misfiring at times and just don't have the power it should. I have replaced plugs and wires and egr valve, fuel pressure is steady at 52lbs. Any ideas where to go next?

 

I had a similar problem on a 98 2.5 Avenger... Cleaned EGR(2 months old) and IAC, no help... ended up being the distributer cap( less than a month old) had a very tiny internal crack...

 

Thanks for the reply. This car has electronic ignition so no dist cap. I did check the coil pack and compared to a new one the parts store it ohmed out exactly the same. Haven'T ruled out the coil pack at the moment since it has some electronics in it that don't allow a full check of the secondary windings of the coil but for $75 don't want to just jump in and change it out yet.

 

I'd run some seafoam thru the intake tract .... might be a bad IAC or dirt in theTB

 

I tried seafoam in the gas in case it was an injector and cleaned the IAC and throttle body. No help.

 

cleaning the IAC doesn't rule out that it's bad ....

 

Try spraying all the vacuum lines,hoses and intake manifold with starter fluid while the motor is running if the idle jumps or becomes more irregular you have and located the vacuum leak that may be causing the problem the only time a leak would throw out a code is when it is near a sensor so try it out and good luck.