Fixing catalytic converter is matter of choice

testing where I live, in Indiana. Please tell me how dangerous it is to drive with a “bad” catalytic converter. Will it destroy my engine? Will fumes back up into my front seat and make me drive into opposing traffic? Thanks. — Marlyce

A 2012 Ford Fiesta ... you lucky devil! Here’s the good news, Marlyce: Driving with a plugged-up catalytic converter shouldn’t permanently harm your car.

At some point, if the converter gets completely plugged up, it’ll diminish your power. And eventually it’ll prevent the car from running at all. It’d be like having a potato in your tailpipe. Then you’ll have to remove the converter if you want the car to run again.

As long as the exhaust system is intact, without leaks, you won’t get any fumes in the passenger compartment. Of course, the same can’t be said for the poor jamokes who are driving behind you.

The bad news, Marlyce, is that it’s illegal to remove your catalytic converter. Federal law sets baseline emissions requirements for all cars in the United States, and gasolinepowered cars can’t meet those emissions requirements without catalytic converters.

Actually, you don’t say how many miles are on your Fiesta. But emissions components — including catalytic converters and oxygen sensors — are all under warranty for eight years or 80,000 miles. So if you’ve got 79,999 miles on the odometer, have it flat-bedded to the dealer and get that stuff replaced for free.

If you’re out of warranty, I can’t tell you what to do, Marlyce. But if I could, I’d tell you to be a good citizen and replace the converter.