Erratic/High Idle

[tmontague]

Easiest way it to buy an ultragauge (or other scan tool) and set it on short and long term fuel trim while the car is idling. Then Rev the car to 2500rpm an see how the values change.

If the long term trim is showing a high positive # under idle but not at 2500rpm then it likely has a vacuum leak.

You should hear a his from the area that is leaking. I personally light a stick of incense and watch where the smoke is being sucked into on the engine to find the specific area of a leak.

Keep in mind after resetting the ECU your engine will idle a little erratically for a few hundred km's