Advanced Engine Diagnostics FAQ – Part 2

1. Can a dirty MAF sensor cause engine issues?

Yes. A dirty mass airflow sensor can lead to incorrect air-fuel ratio readings, causing rough idle, hesitation, or even stalling. Cleaning or replacing it can restore performance.

2. What’s the difference between a scan code and a real diagnosis?

Scan codes provide general fault indicators. A full diagnosis includes live sensor data, mechanical checks, and professional interpretation to find the root cause.

3. What causes a lean or rich engine condition?

Lean conditions come from vacuum leaks or low fuel pressure; rich conditions may be caused by leaking injectors, faulty sensors, or bad fuel regulators.

4. Why does my engine hesitate during acceleration?

This may be due to throttle body issues, bad ignition coils, or weak fuel delivery. We’ll inspect spark, fuel, and air systems during diagnosis.

5. How does temperature affect engine diagnostics?

Some issues only appear when the engine is hot or cold. We simulate different conditions during testing to catch intermittent or heat-related faults.

6. My car stalls randomly. What should I check?

Random stalling can be caused by failing sensors, ignition switches, or wiring faults. A proper diagnostic helps avoid unnecessary part replacements.

7. What is a “pending” code in engine diagnostics?

A pending code means the system has detected an issue once, but needs to see it again before turning on the check engine light. It’s an early warning.

8. How do you check for vacuum leaks?

We use smoke machines or propane testing to safely identify vacuum leaks in hoses, intake manifolds, and PCV systems.

9. Can bad fuel quality trigger engine codes?

Yes. Contaminated fuel can cause misfires, clogged injectors, or improper combustion. We may take fuel samples if quality is suspected.

10. Is engine misfire always an ignition issue?

Not always. Misfires can be caused by fuel, air, mechanical (like low compression), or sensor-related problems. Diagnosis is key.