Rough idle

[dalmo]

02 4WD. Last week the check engine light and the 2 vsc lights came one and with a rough idle. Last week I ended up disconnecting the battery and open and closed the gas cap to make sure its tight. The lights all went away, but it still idles rough at around 400-500 rpm, the car drives fine until i come to a stop. I did not pull any codes. Any ideas ?

Thanks

 

[brian2sun]

The CEL went off only because you disconnected the battery. The codes will still be stored in memory. You need have them read 1st and then we can help you go from there. It's probably a P0100-0106 code (misfire).

 

[TheDurk]

The CEL went off only because you disconnected the battery. The codes will still be stored in memory. You need have them read 1st and then we can help you go from there. It's probably a P0100-0106 code (misfire).

Brian, I thought the codes go away with a power disconnect and it will just report a "Test Not Ready' until it sets the new one (assuming the condition is still present.) It may store the FIRST new one, until it gets the required second detection for the light where two are required. This IS the case with a code reset from a scanner which is what I do. I've never done the battery thing so I could be wrong about what happens there.

 

[brian2sun]

AFAIK, if you reset it with a scan tool, what you said is correct. But it I think when you just pull the cable off the batt, it only turns the CEL off but keeps the codes. But now I'm 2nd guessing myself, haha. In the past, I tried to pull the cable off the batt to turn off the CEL to pass a smog test when my knock sensor went bad, but the smog place still caught it and I had to replace the sensor before they would pass me (even though the CEL was off). I just figured they must have pulled some codes out of the memory. Hmm...

 

[dalmo]

Well I ran a scan and no codes came out. What I ended up doing was I cleaned out the throttle body area, I pulled apart the plastic that connects to it coming from the air filter, I started it up and rmp's jumped from 400 to about 600-700 now and no more rattle. I hope this isnt a temp fix for a week.