OBD-II Generic Error Code P2273: How to Fix It

Q: What does P2273 mean on my car?

P2273 means the Engine Control Module has detected that the heated oxygen sensor on Bank 2, Sensor 2 (the downstream sensor after the catalytic converter on the side of the engine without cylinder 1) is sending a signal that is stuck in a rich state. Instead of producing a normal voltage reading or a steady mid-range signal, the sensor is fixed at a high voltage suggesting excess fuel, and the ECM cannot use it to accurately monitor exhaust and catalyst performance.

Q: Can I drive with a P2273 code?

In most cases, you can drive short distances with P2273 without immediate mechanical danger since it is rated as a medium-severity code. However, a faulty downstream O2 sensor can prevent the ECM from detecting catalytic converter failure, may affect fuel trims over time, and will cause your vehicle to fail an emissions inspection. It is best to diagnose and repair it promptly rather than ignoring it.

Q: How much does it cost to fix P2273?

If the fix is simply replacing the Bank 2 Sensor 2 oxygen sensor, you can expect to pay $20–$100 for the sensor part depending on the brand and vehicle, plus 30–60 minutes of labor if a shop does the work ($50–$120 in labor typically). If the root cause is a rich-running engine condition (injectors, MAF sensor, etc.) or a failed catalytic converter, costs can range from $150 to $1,500 or more depending on what needs to be replaced.

Q: Is Bank 2 Sensor 2 the upstream or downstream sensor?

Sensor 2 always refers to the downstream oxygen sensor — the one located after the catalytic converter. Bank 2 refers to the side of the engine that does NOT contain cylinder number 1. On most inline 4-cylinder engines there is only one bank, so Bank 2 codes typically appear on V6, V8, or other multi-bank engines. Check your vehicle's service manual or a bank diagram specific to your engine to confirm the physical location.

Q: Will P2273 cause a failed emissions test?

Yes, P2273 will very likely cause your vehicle to fail an emissions inspection. An active check engine light is an automatic failure in most U.S. states and many other jurisdictions. Even if the light is cleared before the test, the OBD readiness monitors related to the oxygen sensor and catalyst will show as 'Not Ready,' which is also a failure. The code must be properly repaired and a full drive cycle completed before the vehicle will pass.

Abstract

Error code P2273 means the downstream heated oxygen sensor (HO2S) on Bank 2, Sensor 2 is sending a signal that is permanently stuck in a rich condition — indicating more fuel than air in the exhaust — instead of switching back and forth as it should. This sensor sits after the catalytic converter on the side of the engine that does NOT contain cylinder 1, and its job is to monitor catalytic converter efficiency and exhaust gas composition. When the Engine Control Module (ECM) detects this stuck-rich signal, it triggers the check engine light and may affect fuel trim, emissions, and overall engine performance.