Skip the auto shop - Our mechanics make house calls

Q: Changed catalytic converter, no lights on dashboard, but codes for catalytic converter & O2 sensor still remain

asked by on

Changed catalytic converter, no lights on dashboard, but codes for catalytic converter & O2 sensor still remain

My car has 129000 miles.
My car has an automatic transmission.

A: Hi there, thanks for writing in. I am not s...

Hi there, thanks for writing in. I am not sure why you changed your catalytic converter. Assuming you had a P0420 code, replacing the catalytic converter should of resolved that code. The codes originally stored need to be cleared. The fact your check engine light remains off tells me, you may have fixed the problem. Try disconnecting the negative battery terminal for at least 2 minutes, reconnect. Start and drive the vehicle for 10-15 miles. Re-check for codes. If a code returns on the first drive cycle (pending code), a problem still exists. The check engine light should come back on (the next drive cycle) if, the fault is recognized by the computer. An exhaust leak before the oxygen sensor will cause O2 sensor and catalytic converter codes. If you are having trouble identifying the fault, consider having an expert automotive technician from YourMechanic come to your home or office to inspect and diagnose this issue for you, and make or suggest any repairs as needed.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Acura sounds like...

Hi there. We're not quite clear on what you are referring to when you state that the "Acura sounds like it's accelerating at 40 mph and up". If you mean the RPM is higher than it should be, it's possible...

Q: Car doesn't run after Check Engine light came on

Hi there. When the check engine light starts flashing that means that the engine is experiencing a cylinder misfire. If the engine ended up stalling afterwards then you may have a fuel pump that failed or possibly a timing belt...

Q: How do I fix O2 sensor heater cylinders 1-6 circuit malfunction?

The oxygen sensor heater is integral to the sensor assembly itself. It is not separately serviceable. If the heater tests bad, the entire sensor is replaced as an assembly. In your case, P1193 refers to an oxygen sensor which is...

Related articles

P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the P0052 code means This code is seen when the Engine Control Module (ECM) tries to control the...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...