For 1990-2009 cars

1. Remove the air cleaner intake duct. Refer to Air Cleaner Inlet Duct Replacement .
2. Fully open the throttle valve in order to Inspect the throttle body bore and the throttle valve plate for any deposits.

Notice: Do not subject a throttle body assembly which contains the following components to an immersion cleaner or a strong solvent:

• | Throttle position (TP) sensor

• | Idle air control (IAC) valve

• | Sealed throttle shaft bearings

The cleaners will damage the electric components or sensors. The cleaners will damage some of these components that contain seals or O-rings. Solvents can wash away or break down the grease used on non-serviceable throttle shaft bearings. Never use a wire brush or scraper to clean the throttle body. A wire brush or sharp tools may damage the throttle body components. Do not use a cleaner that contains methyl ethyl ketone. This extremely strong solvent may damage components and is not necessary for this type of cleaning.
3. Use a clean shop towel and Top Engine Cleaner GM P/N 1052626 or equivalent product in order to clean the throttle body bore and the throttle valve plate.

If necessary, use a parts cleaning brush in order to remove heavy deposits.

4. Install the air cleaner duct. Refer to Air Cleaner Inlet Duct Replacement .