Keeping your car in shape

Most new cars come with a catalytic converter for cleaner exhaust emissions. Its purpose is to burn unburned hydrocarbons in the exhaust.

The catalytic converter is lined with special reactive chemicals which deplete over time, so just because one looks intact and hasn't rusted through doesn't mean it shouldn't be replaced.

If you smell unburned fuel even when the engine is warmed up, and your engine is running smoothly and efficiently otherwise, the converter is the prime suspect.

Catalytic converters are usually the most expensive emissions component to replace, so pay attention to other minor problems that might reduce its life.

Check exhaust seals while you're at it. If leaky, these can reduce the back pressure in your exhaust system and interfere with the proper operation of the catalytic converter.

If a seal is leaky, your engine might start to sound slightly different or idle roughly, but sometimes it takes a mechanic's leak test to spot the problem.