Engine Controls - Tests W/O Codes: Backfire: Intake
- Ensure there are no vacuum leaks into intake system.
- Ensure ignition timing is within specification.
- Remove vacuum hose from fuel pressure regulator and monitor for symptom change. (Clean injector if improves).
- Enter self-diagnostic Mode II and monitor fuel metering system operation.
- Disconnect exhaust gas sensor and monitor change in driveability. If it improves, replace sensor. If not, go to 4.
- For Airflow Meter: Enter self-diagnostic Mode III and retrieve codes. If vehicle will not start, crank engine before entering self-diagnostic Mode III.
- For Airflow Meter: Enter self-diagnostic Mode V and monitor real-time diagnostic setting of fault codes. Perform appropriate code chart in TESTS W/CODES article.