Q: I AM GETTING CHECK ENGINE LIGHT AND CODE P0420

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MY CHECK ENGINE LIGHT CAME ON READING CODE P0420 COULD IT BE MY OXYGEN SENSOR DOWNSTREAM, OR BOTH SENSORS OR CATALYTIC CONVERTER SINCE MY MILEAGE IS HIGH 120000 MILES

My car has 120000 miles.
My car has an automatic transmission.

Hi Cornelius. Thanks for contacting us today. The P-0420 typically has to do with the catalytic converter in your vehicle, but can be triggered by damaged by O2 sensors, exhaust manifold or exhaust pipe leaks, or wiring harnesses that relay data to the ECU from these sensors. If all these sensors check out and there are no wiring issues or exhaust leaks, then the catalytic converter may need to be replaced. You might want to read this article on the P-0420 OBD-II code to learn more about possible repairs and diagnosis tips.

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