* Faulty MAF Sensor: This is the most common cause. The sensor itself might be dirty, damaged, or failing. Dirt, oil, or other contaminants can interfere with the sensor's ability to measure the airflow accurately.
* Wiring Problems: A break, short, or poor connection in the wiring harness leading to or from the MAF sensor can disrupt the signal. Check the connector for corrosion or loose wires.
* Vacuum Leaks: A vacuum leak before the MAF sensor can cause less air to reach the sensor than the engine is actually using, leading to a low input reading.
* Air Filter Restriction: A severely clogged air filter will restrict airflow, resulting in a lower reading from the MAF sensor. This is less likely to trigger a P0102 specifically, but a very dirty filter can contribute.
* Improper MAF Sensor Installation: If the MAF sensor was recently replaced, it might not be seated correctly.
* Rarely, ECM Problem: While less likely, a faulty ECM could also contribute to the issue. This is usually diagnosed after checking all other potential problems.
Troubleshooting Steps:
1. Check the Air Filter: Replace it if it's dirty.
2. Inspect the MAF Sensor: Look for any visible damage, dirt, or debris. Carefully clean it with MAF sensor cleaner (do not use anything else; brake cleaner, etc., will damage it). Ensure you follow the cleaner's instructions precisely.
3. Inspect the Wiring: Check the wiring harness connecting the MAF sensor to the ECM for any damage, breaks, loose connections, or corrosion.
4. Check for Vacuum Leaks: Inspect all vacuum hoses and connections for cracks or leaks.
5. Test the MAF Sensor: This often requires a multimeter and some knowledge of automotive electronics. A professional scan tool can also provide more detailed MAF sensor readings.
6. Clear the Code: After addressing any potential problems, clear the code using an OBD-II scanner and see if it returns.
If you're not comfortable performing these checks yourself, it's best to take your Impala to a qualified mechanic for diagnosis and repair. Replacing the MAF sensor is often a relatively inexpensive fix, but misdiagnosis can lead to unnecessary expenses.
