P2273 2015 Chevrolet Silverado Code - HO2S Signal Stuck Rich Bank 2 Sensor 2

P2273 indicates that the downstream oxygen sensor (Bank 2, Sensor 2) has detected a consistently rich air-fuel mixture, meaning there is too much fuel or insufficient oxygen in the exhaust gases.

Common symptoms include a check engine light, reduced fuel efficiency, increased emissions, and possible rough idling or poor engine performance.

Potential causes include a faulty downstream oxygen sensor, exhaust leaks, a malfunctioning fuel injector, a clogged air filter, or issues with the engine control module (ECM).

The code refers to Bank 2 (the side of the engine opposite Cylinder 1) and Sensor 2, which is the oxygen sensor located downstream of the catalytic converter.

Yes, a failing or clogged catalytic converter can cause the downstream O2 sensor to read a rich condition and trigger the P2273 code.

While the vehicle may still be drivable, ignoring the code can lead to worsened fuel efficiency, increased emissions, and potential damage to the catalytic converter over time.

A mechanic will use an OBDII scanner to confirm the code, inspect the downstream oxygen sensor and wiring, check for exhaust leaks, and evaluate the fuel system and air intake components.

If you have basic automotive knowledge, you can inspect for obvious issues like damaged wiring, a clogged air filter, or exhaust leaks. However, advanced diagnostics or sensor replacement may require professional help.

Repair costs vary depending on the cause. Replacing a downstream oxygen sensor typically costs $150–$300, while catalytic converter repairs or fuel system work can be more expensive.

Clearing the code will turn off the check engine light temporarily, but if the underlying issue isn’t fixed, the code will reappear. Proper diagnosis and repair are necessary.