Check Engine Light On? Here's What to Do
Don't ignore that check engine light! Learn what it means, common causes, and when to seek professional diagnosis.
Emergency Warning
If your check engine light is flashing, stop driving immediately and call us. A flashing light indicates a serious problem that could damage your engine.
What to Do When Your Check Engine Light Comes On
Immediate Steps
- 1 Check if the light is steady or flashing
- 2 Look for obvious issues (loose gas cap, unusual noises)
- 3 Check your gas cap - a loose cap is a common cause
- 4 Schedule a diagnostic appointment within a few days
When to Seek Immediate Help
- Flashing check engine light
- Engine running rough or stalling
- Loss of power or poor performance
- Unusual noises or smells
Common Check Engine Light Causes
Loose Gas Cap
The most common cause. Tighten your gas cap and drive for a few days to see if the light goes off.
Faulty Oxygen Sensor
Monitors exhaust gases. A bad sensor can reduce fuel economy and cause emissions issues.
Catalytic Converter
Reduces harmful emissions. Failure can cause poor performance and increased emissions.
Mass Airflow Sensor
Measures air entering the engine. A dirty sensor can cause poor fuel economy and performance.
Spark Plugs/Ignition
Worn spark plugs or faulty ignition coils can cause misfires and poor performance.
Evaporative System
Controls fuel vapor emissions. Leaks can cause the check engine light to come on.
Common Diagnostic Trouble Codes
P0300 - Random/Multiple Cylinder Misfire
Engine misfiring in multiple cylinders
- Faulty spark plugs
- Bad ignition coils
- Clogged fuel injectors
- Low fuel pressure
P0171/P0174 - System Too Lean
Air/fuel mixture is too lean
- Dirty mass airflow sensor
- Vacuum leak
- Faulty oxygen sensor
- Clogged fuel filter
P0420 - Catalyst System Efficiency Below Threshold
Catalytic converter not working properly
- Faulty catalytic converter
- Bad oxygen sensor
- Engine running rich
- Exhaust leak
P0442 - Small Evap Leak
Small leak in evaporative emission system
- Loose gas cap
- Cracked evap hose
- Faulty purge valve
- Leaking fuel tank
Our Diagnostic Process
What We Do
- 1 Computer Scan: Connect our diagnostic scanner to read trouble codes
- 2 Code Analysis: Interpret the codes and identify the root cause
- 3 Visual Inspection: Check for obvious issues and component condition
- 4 Repair Options: Provide detailed estimate with repair options
Why Choose Our Diagnostics?
- Latest diagnostic equipment for all makes and models
- ASE-certified technicians with years of experience
- Diagnostic fee applied toward any repairs
- Honest recommendations - we won't sell you unnecessary repairs
Need Check Engine Light Diagnosis?
Don't ignore that check engine light! Our expert technicians can quickly diagnose the problem and get you back on the road safely.