Signs of a failing catalytic converter
The catalytic converter sits in your exhaust and cleans up the gases coming out of the engine. When it starts to fail, you’ll usually notice one or more of these:
- Check engine light on, often with a converter efficiency code
- Sluggish acceleration, especially going uphill
- A rotten egg or sulfur smell from the exhaust, sometimes with a lot of heat under the car
- Dark exhaust smoke
- Worse fuel mileage than usual
- A rattle underneath, or in bad cases, an engine that stalls or won’t start
None of these prove the converter is bad on its own. A converter code can also come from a faulty oxygen sensor or an exhaust leak, and both cost far less to fix. That’s why we test before we replace.
Why converters fail
Converters rarely just wear out. Something upstream usually damages them. An engine that misfires, burns oil or leaks coolant sends unburned fuel and contaminants into the converter. It overheats, the inside melts or clogs, and exhaust can’t flow freely.
So when we diagnose a converter, we also look at why it failed. If an engine problem caused it, that needs fixing too, or the new converter will go the same way. In that case we may recommend engine repair first and explain why. Keeping up with your factory scheduled maintenance is one of the best ways to protect a converter in the first place.
Catalytic converter theft
Converters contain precious metals, which makes them a target for thieves. A stolen converter usually shows up as a loud roar on startup and a check engine light. Driving that way isn’t a good idea, because exhaust can find its way into the cabin.
We replace stolen converters and check the cut pipes, oxygen sensors and wiring that often get damaged in the process. Trucks and SUVs that sit higher off the ground are easier targets, so parking in a garage or a well-lit spot helps.
What affects the cost of replacement
Converter jobs vary a lot from one vehicle to the next. Some engines have the converter built into the exhaust manifold, which takes more labor to reach. V6 and V8 engines often have two or more converters. Rusted bolts and seized oxygen sensors, common on older cars, add time too.
We’ll give you a clear estimate before any work starts, along with anything else we found, like a leaking pipe or a worn-out muffler. We’ll tell you what needs doing now and what can wait, and work with your timeline and budget.
Bring it in for a converter check
Call 425-420-1630 or request an appointment below. If your check engine light is flashing, keep driving to a minimum. A flashing light means an active misfire, and that can ruin a converter quickly. Our early morning and late night key drop box makes it easy to leave the car on your way to work.
We’re at the back of Bear Creek Plaza near Hwy 522, and we work on all makes and models, domestic and import.