1. Safety First:
* Disconnect the negative battery terminal. This prevents accidental shorts and protects your vehicle's computer.
* Gather your supplies: You'll need throttle body cleaner (specifically designed for this purpose – *not* brake cleaner), clean rags or shop towels, a small brush (like a toothbrush), and possibly a can of compressed air. Safety glasses are also recommended.
* Work in a well-ventilated area. Throttle body cleaner is flammable and produces fumes.
2. Accessing the Throttle Body:
* Locate the throttle body. It's usually located on the intake manifold, near the air filter housing. Refer to your Trailblazer's repair manual or consult online resources (with pictures!) for the precise location.
* Remove the air intake duct. This often involves unclipping or loosening clamps. Take your time and avoid breaking anything. Photograph the process if you're unsure about reassembly.
3. Cleaning the Throttle Body:
* Inspect the throttle body. Note the condition before you start cleaning. Take photos if necessary.
* Lightly spray the throttle body cleaner. Aim for the butterfly valve (the plate that controls airflow) and the surrounding areas. *Avoid spraying directly onto the sensors or electrical components.*
* Gently scrub with the brush. Focus on removing any buildup of carbon deposits or grime.
* Let the cleaner sit for a few minutes. This allows it to dissolve the build-up.
* Spray again with the throttle body cleaner. Then, use compressed air to blow away any loosened debris. Be careful not to damage any sensors.
* Wipe clean with a clean rag. Remove all traces of cleaner and debris.
4. Reassembly:
* Carefully inspect everything again. Ensure all surfaces are clean and dry.
* Reattach the air intake duct. Make sure the clamps are securely fastened.
* Reconnect the negative battery terminal.
5. Important Considerations:
* Don't over-spray. Excessive cleaner can damage sensors.
* Avoid getting cleaner on the Mass Airflow Sensor (MAF) sensor. If you accidentally get cleaner on it, you'll likely need to replace it. The MAF sensor is usually located upstream of the throttle body on the intake tube. Protect it with a plastic bag or cover while cleaning.
* Some throttle bodies are electronically controlled. These have motors that control the butterfly valve. Be very gentle when cleaning around these components.
* If you're uncomfortable performing this task yourself, take your Trailblazer to a qualified mechanic.
This is a general guide. Consult a repair manual specific to your 2002 Chevrolet Trailblazer for detailed instructions and diagrams. Improper cleaning could damage your vehicle. If you are unsure about any step, seek professional help.
