Important: Over extended time and mileage, deposits may accumulate on the back of the throttle valve plate. Occasionally the deposit may accumulate to a point where perceived pedal effort is affected. This procedure should not be performed on vehicles with low mileage, under 80 450 kilometers (50,000 miles).

1. Remove the air intake duct.

Notice: Do not insert any tools into the throttle body bore in order to avoid damage to the throttle valve plate.

2. Inspect the throttle body bore and inspect the throttle valve plate for deposits. The throttle valve must be opened in order to inspect all surfaces.

Notice: Do not use any solvent that contains Methyl Ethyl Ketone (MEK). This solvent may damage fuel system components.

3. Clean the throttle body bore and the throttle valve plate using a clean shop towel with GM Top Engine Cleaner, P/N 1052626 (Canadian P/N 993026) .
4. Install the air intake duct.