A vehicle is in the shop because it failed an emissions test due to excessive carbon monoxide (CO). The fault was a bad oxygen sensor that was easily replaced. Technician A says that the EGR system should be checked before the vehicle is retested. Technician B says the vehicle should be tested with a five-gas analyzer before it is retested. Who is correct?

Question

Quizplus · Accepted Answer

Both technicians are correct. Checking the EGR (Exhaust Gas Recirculation) system can help ensure it is functioning properly and not contributing to the emissions problem. Using a five-gas analyzer can provide a comprehensive view of the vehicle's emissions, including CO, to ensure the issue has been resolved before retesting.

A Vehicle Is in the Shop Because It Failed an Emissions