How Long Do Catalytic Converters Last?

The truth is, on modern vehicles, the catalytic converter should last at least 10 years. Some people may not need their catalytic converter replaced during the life of their vehicle. Good thing, too, because this auto part uses rare, precious and therefore expensive metals such as gold, palladium, platinum or rhodium. They act as catalysts in chemical reactions that convert air-polluting oxides of nitrogen, unburned fuel and carbon monoxide into plain old nitrogen, carbon dioxide and water.

Sometimes things do go wrong with catalytic converters prematurely. A sharp blow to the unit, after say, bottoming out the vehicle, could damage the catalyst material or the metal housing of the unit. This will block the flow of exhaust gases out the back (and hurt engine performance).

An engine that's burning excessive oil could also wear out a catalytic converter before its time. In addition, certain fuel additives can (and do) counteract and prematurely age the catalysts.

Sometimes a car owner might smell foul odors emanating from the engine or exhaust system. Armchair technicians often blame the funk on a failing catalytic converter -- but it could be any number of things, so you're best advised to have an authorized auto technician check it out.

There is one instance in which you will know for absolute certainty that your catalytic converter needs replacing. And that is if it gets stolen!

Yes, it's sad but true: particularly in tough economic times, thieves are fond of stealing the catalytic converters from parked vehicles to cash in on the expensive metals within. Any vehicle can fall prey, though news accounts say that high-stanced trucks and SUVs make the juiciest targets. A thief can easily slip under a truck and use a reciprocating saw or wrench to remove the catalytic converter from the exhaust system.

The relatively good news is that catalytic converters are free of moving parts and more or less maintenance-free. Unlike tires, filters or brake parts, the catalytic converter on a modern vehicle should not require frequent replacement -- if at all.

We updated this article in conjunction with AI technology, then made sure it was fact-checked and edited by a HowStuffWorks editor.