- Remove the air cleaner intake duct. Refer to 
Air Cleaner Inlet Duct Replacement 
 .
 
- 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.
- 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.
- Install the air cleaner duct. Refer to 
Air Cleaner Inlet Duct Replacement 
 .