How To Diagnose Catalytic Converter Failure

The sole duty of your vehicle’s catalytic converter is to maintain emission levels, converting harmful exhaust elements into safe compounds that cause less damage to the environment. The catalytic converter is a vital component to your vehicle’s exhaust system, and when this component fails, it can hinder the overall performance of your vehicle.

Refer to this guide to learn the symptoms of a failing catalytic converter.

Notice: Catalytic converters can fail in two ways—they can become clogged or poisoned.

Catalytic Converter

1. Performance

  • When your vehicle’s catalytic converter is clogged, exhaust gasses are trapped between the converter and the engine, which causes the performance of your vehicle to drop. There will be a stubborn resistance when you press the gas pedal as if your vehicle is choking, and in worst cases, the heightened level of back pressure in your exhaust route can cause your engine to stall during operation.

2. Fuel Economy

  • Your vehicle’s increased fuel consumption will be quite obvious as a result of a clogged catalytic converter. When the converter is clogged, your vehicle needs a greater amount of fuel to run.

3. Oxygen Levels

  • Since you can’t inspect the internals of a catalytic converter while it’s on your vehicle, temporarily removing the oxygen sensor located in front of the catalytic converter can tell you if your converter is clogged. If there is a noticeable difference in your vehicle’s performance while the oxygen sensor is removed, it’s safe to say your converter is failing.

4. Contamination

  • Catalytic converters can be finicky in terms of operating under the proper temperatures. The internals of the catalytic converter either consists of catalysts or are coated in catalysts that cause a chemical reaction when put up against exhaust gases. Any sort of additives in the exhaust route can cause the exhaust gas mixture and temperature to change, ultimately poisoning your catalytic converter and reducing its effectiveness, allowing heightened levels of carbon emissions.

5. Spark

  • Ignition systems, primarily your vehicle’s spark plugs, can misfire when they’re fouled or your vehicle is running with a rich fuel mixture. Misfiring can cause the unburned fuel to overheat your vehicle’s catalytic converter, damaging or melting the converter’s catalysts.

A faulty catalytic converter will signal a check engine light, and also cause you to fail a state issued emissions test. If you are seeing a check engine light on your dash while the aforementioned symptoms are occurring, it is recommended to replace your catalytic converter immediately to restore your vehicle’s performance and abide by your state’s emission laws.