Catalytic converters can only function efficiently if the engine is operating properly, and the exhaust system is leak-free. Diagnose the cause of emissions problems with 13 key steps.
Customer feedback is an invaluable tool. Driveability, performance and service history can help guide you through the diagnostic process.
Any condition that increases emissions or affects sensor readings could cause a converter to fail diagnostics even if the converter is good.
Leaks in the exhaust system can affect O2 (Oxygen) storage in the converter and lead to improper O2 (Oxygen) Sensor readings, affecting the AFR (Air / Fuel Ratio) balance.
An infrared thermometer can be used to check the temperature of a converter to determine converter lite off.
Excessive system backpressure can generate a converter efficiency code.
O2 (Oxygen) Sensors are critical to fuel control and to the PCM's converter diagnostics.
Internal cooling system leaks can destroy a catalytic converter.
There are many things in the fuel system that can damage a catalytic converter or increase HC (Hydrocarbon) emissions.
The PCM attempts to maintain AFR of 14.7 : 1, using data it receives from the vehicle's sensors, primarily the MAF and O2 Sensors.
One of the most effective ways to resolve emissions issues is by sampling the exhaust gases.
Any cylinder that is not working as hard as the others is the most likely cause of emissions issues.
High-mileage engines can have many mechanical problems that contribute to high emissions.
Re-flashing is the process of updating the PCM (Powertrain Control Module) with the latest program available from the vehicle's manufacturer.