Catalytic converter usage life span

Hi Riebe123, my name is Alex and I will be answering your question today.

There really is no set mileage to replace a catalytic converter. It depends on a lot of variables. The good news is that your vehicle is constantly checking the efficiency of it's catalytic converter. When your catalytic converter, through normal wear and tear, has deteriorated enough that it needs to be replaced, then your vehicle will illuminate it's Malfunction Indicator Lamp(MIL), also known as your check engine light, and your Power-train Control Module(PCM). Computer will store Direct Trouble Code (DTC) 0420 catalytic converter efficiency below threshold. I hope this helps, and thank you for using 2CarPros, Alex.

DTC 0420 is indeed the DTC for replacing your catalytic converter. The upstream O2 sensor is used by your vehicle's PCM to maintain your vehicle's air/fuel ratio as close to stoichmetric (14.7:1) as possible. It is the downstream O2 sensor, or after the catalytic converter, that monitors how efficient your catalytic converter is. The fact that the DTC set after filling up is purely coincidental. Thanks again for using 2CarPros, Alex.