Will My Car Pass Inspection with the Check Engine Light On?
Can a Check Engine Light Cause Inspection Failure?
Yes, in most cases, your car will fail inspection if the check engine light (CEL) is on. The CEL indicates an issue with the engine, emissions system, or other critical components, which often results in a failed emissions test.
Types of Inspections and the Check Engine Light
Why a Check Engine Light Causes Inspection Failure
- Emissions Readiness Monitors Not Set – The car’s computer runs self-tests, and if an emissions issue is detected, the OBD-II scanner will flag it.
- Stored Trouble Codes – Even if the light is off, stored codes in the ECU can still trigger a failure.
- Serious Engine or Sensor Issues – A CEL means the car isn’t running optimally, which can impact emissions and safety.
How to Pass Inspection If the Check Engine Light Is On
✅ Get a Diagnostic Scan – Use an OBD-II scanner to find out why the light is on.
✅ Fix the Underlying Issue – Common causes include oxygen sensor failure, bad spark plugs, or a loose gas cap.
✅ Reset the Check Engine Light – If the issue is fixed, use an OBD-II scanner to clear the codes.
✅ Drive 50–100 Miles Before Inspection – Some states require readiness monitors to reset after clearing codes.
Temporary Ways to Pass Inspection (Not Recommended)
⚠️ Disconnecting the Battery – This resets the CEL but also erases readiness monitors, which may still cause failure.
⚠️ Using a Code Reader to Clear the Light – The inspector’s system will detect if the monitors haven’t completed.
⚠️ Fuel Additives or “Inspection Passing” Kits – Some claim to lower emissions, but they don’t fix the actual problem.
Final Thoughts
In most states, your car will not pass inspection with a check engine light on. Fixing the issue and driving enough for the readiness monitors to reset is the best way to ensure you pass.
FAQs
1. Can I pass inspection if I reset the check engine light?
Only if you fix the actual issue and drive enough for the readiness monitors to reset (50–100 miles).
2. How do I check if my car is ready for inspection?
Use an OBD-II scanner and check the emissions readiness monitors—if they say “complete,” you’re good to go.
3. What are common reasons for a check engine light?
- Loose gas cap
- Bad oxygen sensor
- Faulty catalytic converter
- Spark plug or ignition coil issues
4. What states automatically fail you for a check engine light?
Most states with OBD-II emissions testing (like California, New York, and Texas) require the CEL to be off.
5. How much does it cost to fix a check engine light?
It depends on the cause:
- Loose gas cap: Free – $20
- Oxygen sensor: $100–$300
- Catalytic converter: $500–$2,000
- Ignition coil/spark plugs: $100–$400
Also Check:
• Will the Check Engine Light Turn Off on Its Own?
• Does ToyotaCare Cover Check Engine Light Diagnosis?
• Can Advance Auto Parts Check the Check Engine Light?
