The catalytic converter converts harmful exhaust gases into less harmful ones using a coated honeycomb inside a steel shell. When it fails you get a check engine light, sometimes a rattle, and sometimes a loss of power from a blocked exhaust. AutoTech Clinic tests converters properly at our Dearborn shop before recommending replacement.
A converter code does not automatically mean a bad converter. An exhaust leak, a lazy oxygen sensor or an engine running rich will all set the same code, and all three are cheaper to fix.
- How Long
- Diagnostics about 1 hour. Replacement usually 2 to 4 hours.
- Same Day
- Time frame confirmed before you leave the car.
- Vehicles
- Foreign and domestic, cars through trucks.
Signs You Need Catalytic Converter
- A check engine light with a catalyst efficiency code
- A rattle from under the car that sounds like stones in a can
- A rotten egg or sulfur smell from the exhaust
- A loss of power, especially at higher engine speeds
- The exhaust glowing or smelling very hot after a short drive
- A failed emissions test
What We Do
- 01
Test Before Condemning
We compare upstream and downstream oxygen sensor data and check how the converter responds to a change in mixture. A healthy converter behaves in a distinct way.
- 02
Check for Restriction
We measure exhaust backpressure to see whether the converter has collapsed internally and is choking the engine.
- 03
Find the Underlying Cause
Converters are usually killed by something else: a misfire, a rich mixture, an oil or coolant leak into the exhaust. We find that first.
- 04
Quote the Correct Part
We explain the difference between a direct fit converter and a universal one, and what each means for the warning light and for emissions compliance.
- 05
Fit and Verify
After fitting we run the vehicle through a drive cycle, confirm the monitors complete and verify the light stays off rather than handing the car back untested.
What Actually Kills a Converter
A converter is a chemical device with no moving parts, and in normal service it can outlast the car. The things that kill one are unburnt fuel from a misfire, which melts the honeycomb, and oil or coolant from an internal engine leak, which coats it and stops it working.
That is why we always ask what else the car has been doing. A converter replaced behind an unrepaired misfire will fail again, and that is an expensive lesson to learn twice.
Converter Theft and What It Sounds Like
Converter theft has been a real problem across Metro Detroit. If your car suddenly became extremely loud between parking it and starting it, and the noise is a deep roar from under the middle of the car, check underneath before assuming something failed.
If a converter has been cut out we can quote a replacement and discuss shield options that make the next attempt considerably harder.
What Affects the Cost
We quote your vehicle specifically after inspecting it, because these are the things that move the number up or down:
- Direct fit versus universal converters
- How many converters your vehicle has, since many have two or more
- Whether the oxygen sensors also need replacing
- Rusted flange bolts and pipe sections that have to be cut and replaced
- The repair of whatever caused the converter to fail
Call (313) 277-7200 with your year, make and model and we will tell you what to expect before you come in.
Why AutoTech Clinic
AAA Approved
An inspected facility that has to meet AAA standards for equipment and training.
Photos First
You see what we found and approve the price before anything is taken apart.
Same-Day Service
Parts on hand for the vehicles we see most, so you are not waiting on a delivery.