Will My Car Pass Inspection with the Check Engine Light On?
Introduction
The check engine light (CEL) is a dashboard light that illuminates when the engine control module (ECM) detects a problem with the engine or its emissions system. When the CEL is on, it means that the ECM has stored a diagnostic trouble code (DTC) in its memory. DTCs are codes that identify the specific problem that has been detected.
In most states, vehicles are required to pass an emissions inspection in order to be registered. Emissions inspections are designed to ensure that vehicles are not emitting excessive amounts of pollutants into the atmosphere.
If your car’s CEL is on, you may be wondering if it will pass an emissions inspection. The answer to this question depends on the specific DTC that has been stored in the ECM’s memory.
DTCs That Cause the CEL to Illuminate
There are many different DTCs that can cause the CEL to illuminate. Some of the most common DTCs include:
- P0420: Catalyst system efficiency below threshold
- P0440: Evaporative emission system leak detected
- P0455: Gross evaporative emission leak detected
- P0456: Evaporative emission system small leak detected
- P0460: Fuel level sensor circuit malfunction
- P0505: Idle air control system malfunction
- P0507: Idle air control system circuit low
- P0508: Idle air control system circuit high
DTCs That Will Cause an Emissions Inspection Failure
Not all DTCs will cause an emissions inspection failure. However, some DTCs will cause the vehicle to fail an emissions inspection. These DTCs include:
- P0420: Catalyst system efficiency below threshold
- P0440: Evaporative emission system leak detected
If your car’s CEL is on and you are concerned about passing an emissions inspection, it is important to have the DTCs diagnosed by a qualified mechanic. The mechanic will be able to determine if the DTCs are related to an emissions system problem. If the DTCs are related to an emissions system problem, the mechanic will be able to repair the problem and reset the CEL.
How to Prepare for an Emissions Inspection
If your car’s CEL is on, there are a few things you can do to prepare for an emissions inspection:
- Have the DTCs diagnosed by a qualified mechanic.
- If the DTCs are related to an emissions system problem, have the problem repaired.
- Reset the CEL.
- Drive the car for at least a few days before the emissions inspection.
By following these steps, you can increase the chances of your car passing an emissions inspection with the CEL on.
Conclusion
In most states, vehicles are required to pass an emissions inspection in order to be registered. If your car’s CEL is on, you may be wondering if it will pass an emissions inspection. The answer to this question depends on the specific DTC that has been stored in the ECM’s memory. Some DTCs will cause an emissions inspection failure, while others will not. If you are concerned about passing an emissions inspection, it is important to have the DTCs diagnosed by a qualified mechanic. The mechanic will be able to determine if the DTCs are related to an emissions system problem. If the DTCs are related to an emissions system problem, the mechanic will be able to repair the problem and reset the CEL.
