When I'm stopped at a light or something and I'm idling,the rpm's jump around a little and I can feel my car vibrate with them. It's sporadic and can happen close together or far apart. Can it be various different things or is this always a symptom of one thing?

 

-MAF
-ETM

These are my ideas.

 

Check the Idle motor hose from the Intercooler to the intake manifold.

 

Or the IAC motor, no ETM on this model

 

Well, my "check engine" light came on, so I took it to Autozone to check the codes. Came back as "Cylinder 3 misfire". The guy said thatit looks like it's time for a tuneup. Does that sound about right at 77K miles? I bought spark plugs a few weeks back and was planning on installing them this weekend. I'm now wondering if that will fix the problem.

 

Well replacing spark plugs wouldn't hurt to try. cheapest way to see if it fixes a misfire. if not further tracing will be needed. Also visually inspect the all plugs wirings and coil wirng and see fi there are visual damage.

 

Well, I successfully changed my spark plugs this weekend. That seemed to havefix my idling problem. However, my check engine light is still on. Should that have gone away if that fixed my cylinder 3 misfire? Or is there a chance that the 2 problemswere unrelated?

 

Misfire set a code. Even though the plugs may have corrected the problem the light will stay on until the code is cleared.

 

Thanks. When you say until the code is clear did you mean automatically or manually? The reason I ask is because I was just driving it and the light went away.

 

There could be 2 possible causes with this one. 1st have the fuel pressure regulator checked this could cause the problem and is common. 2nd could be the VVT solenoid and or the unit, this will cause misfire DTCs. Spark plugs are easy, but they IMO are not the problem alone.