[grubin]

Has anyone else have this problem After the dealer did the 30k service whenever the car is at a stoplight or at idle it semes to be bouncing as if there was bad gas(which there is not) or ? That kind of feeling. Had it back twice but the same thing as the engine warms up the problem begins
Otherwise the car runs fine as always just at stop or idle?

The dealer now says heads but ?????

 

[Joewild]

Did they replace oxygen sensors? Some else had this problem when the oxygen sensors where replaced with Bosch sensors instead of Denso. May be something to look at if they did change them out. From what I under stand the Bosch heat up different from the Denso which I guess makes the engine idle a little rougher but not enough to set off the check engine light.

 

[Frango100]

The problem with Bosch sensors is that they heat up more slowly then the Densos and the PCM is timing this and set a fault code. There is otherwise no difference between those two brands.
Would be quite early to change the O2 sensors at 30.000, especially when it was running fine before the service.