Q: What causes a catalytic converter to fail?
A: A rich fuel mixture can cause the catalytic converter to prematurely fail. If unburned fuel enters the converter, it can overheat. The exhaust gases can be analyzed to determine if the air/fuel mixture is correct. An overuse of some fuel additives can also shorten the converter’s life. A loss of power, poor fuel economy, or engine missing can be signs of a clogged converter. A catalytic converter often lasts the lifetime of the vehicle. But if you are having a problem, be sure to check your owner’s manual for the emissions system warranty. Often this warranty exceeds the car’s normal warranty.