Q: I had the catalyst converter replaced last year. Now the Check Engine Light is on again for O2 sensor. What do I do?

asked by on October 20, 2016

I had the catalyst converter replaced last year but now the check engine light is on again for the o2 sensor and catalyst converter why am i having this issue again with the impala what could possibly be going on to cause emission failure with a fairly new replaced converter?

My car has 72000 miles.
My car has an automatic transmission.

Oxygen Sensor Replacement $108.80 - $869.59 Get a Quote
Check Engine Light is on Inspection $79.99 - $89.99 Get a Quote

You may want to have a professional inspect the catalytic converter. When the Check Engine Light comes on for this, it does not necessarily mean that the catalytic converter has failed. This may be related to many other things as well such as the O2 sensor making false readings or potentially a rich or lean fuel mixture being caused by something else.

To avoid any unnecessary repairs, I would recommend having one of our mobile experts come out to you to do a proper diagnostic test using a scanning tool to download the car’s trouble codes and inspect the catalytic converter.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

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

What others are asking

Obd1 code 45 car miss firing and stalling

The carburetor on these cars have a mixture control solenoid that goes bad and I would suggest replacing the solenoid if you got a Code 23 with or without Codes 44 and 45. Since you overhauled the carburetor, the adjustment...

Bad ball joints and wheel bearings

Depending on the severity of this, you should be fine making the drive. Generally, when either the ball joints or wheel bearings catastrophically fail, there is ample warning and plenty of symptoms ahead of time. I would agree with what...

Spark plug threads

It sounds like you may have a stripped spark plug thread in the cylinder head. This can sometimes be fixed by the use of a Heli-coil, which may be a bit difficult to use depending on your experience with them....

How quickly should I take my car to the shop? It says service ecm. How much does this usually cost?

Hello, thank you for writing in. While there is typically not a designated warning light for the ECM (electronic control module), there may be a check engine light pertaining to it. If you pulled a code for the ECM, further...

Car shakes when put in park

You should start by checking for a failed head gasket. With the overheating and coolant loss you describe, followed by very rough running suggests one or more cylinders have lost compression, causing the engine to shake. It's also worth having...

Oil pressure goes to 0 after 1 minute from start up

The engine specifications are 6 psi below 1000 rpms. It will go up 18 psi at 2000 rpm and 24 psi at 4000 rpm. The instrument panel will illuminate the Low Oil Pressure Light if the pressure is low from...

How can I be sure i am having a Throttle Position Sensor issue?

Typically a throttle position sensor (TPS) is tested using a multimeter. The specs to compare against are published in the Factory Service Manual. As long as the TPS tests within the range of published values, and does not display intermittent...

Fuel fill inlet

Hi...thank you for your question and I will try to help you with the issue. ALL faults that cause the check engine light to illuminate have to be resolved, with the light ultimately extinguished, because once the check engine light...

I am having a problem with my tension pulley bearing/bolt.

Hi Val. Thanks for contacting us today. In short - yeah, this is likely not going to work for you long term. Remember, when metal heats, most adhesives will fail. The right way to resolve this issue, unfortunately, is to...

Related articles

P0347 OBD-II Trouble Code: Camshaft Position Sensor A Circuit Low Input (Bank 2)
P0347 P0347 code definition The P0347 Trouble Code refers to an issue with the camshaft position sensor A where the circuit input in bank 2 is too low. What the P0347 code means This is a generic code regarding...
P2003 OBD-II Trouble Code: Diesel Particulate Filter Efficiency Below Threshold Bank 2
P2003 P2003 trouble code definition P2003 is a generic diagnostic trouble code (DTC) that indicates a fault with the Diesel particulate filter. This code is identical to the P2002 code except that P2002 is for bank 1. What the P2003...
P0698 OBD-II Trouble Code: Sensor Reference Voltage “C” Circuit Low
P0698 means there is an irregular voltage level or connectivity problem relating to the electrical circuitry due to faulty wiring or connections.