Emission System Diagnosis & Testing Cost Estimate

Diagnosis of the emissions system will nearly always begin by connecting a professional grade diagnostic scan tool to the vehicle. That is because the OBD-II trouble codes stored in the ECU will need to be accessed, read, and evaluated. This is normally the first step towards diagnosis. The subsystem registering the fault will then need to be inspected, tested, and the faulty component will be identified and proven faulty before recommending a repair.

RepairPal recommends the proper maintenance and repair of all emissions systems for every vehicle. Although many states do not inspect the operation of the emission systems, these systems are put in place to protect the environment to the best of our ability. Depending on location, removal or tampering with the emissions system may be illegal, and, at the very least, the vehicle will likely lose a considerable amount of fuel efficiency.

The check engine light warns drivers about issues related to emissions control systems. You may notice that many things, like spark plug replacement, may cause the check engine light to turn off, and wonder why that would be an emission related component. This is because the efficiency of the engine is controlled to a high degree to reduce harmful emissions, and a bad spark plug will cause elevated harmful emissions. This is why so many subsystems play a role in emission control.

Diagnosing the emission system is likely more difficult than many DIY mechanics will reasonably choose to take on. That being said, there are many components that can be easily diagnosed and repaired, but, in general, check engine light diagnosis and emission system diagnosis should be left to a professional if the cause and remedy are not readily identifiable.