P2273 O2 Sensor Signal Biased/Stuck Rich Bank 2 Sensor 2
OBD-II Trouble Code Technical Description
O2 Sensor Signal Biased/Stuck Rich Bank 2 Sensor 2
What does that mean?
This is a generic powertrain code, which means it covers all OBD-II equipped vehicles, 1996-newer. Auto brands may include but are not limited to Hyundai, Ford, Jeep, Chevy, BMW, Kia, Holden, Dodge, etc. However, specific troubleshooting steps will vary depending on the vehicle.
总裁俱乐部appThis P2273 diagnostic trouble code (DTC) refers to the post-catalytic converter O2 (oxygen) sensor on bank #2, sensor #2. This post-cat sensor is used for monitoring the efficiency of the catalytic converter. The converter's job is to reduce emissions out the tailpipe. When the signal from the O2 sensor is detected by the PCM as being stuck Rich or biased Rich, this DTC is set.
The P2273 DTC refers to downstream sensor (after the catalytic converter), sensor #2 on bank #2. Bank #2 is the side of the engine that does not contain the #1 cylinder. There may be a third sensor downstream, if that is the problem, a P2277 is set.
This code is basically telling you that the signal put out by the particular oyxgen sensor is stuck rich (meaning too little air in the exhaust). It is somewhat common to see both the P2271总裁俱乐部app and P2273 codes set at the same time, depending on the vehicle and root cause of the problem.
A typical oxygen O2 sensor:
总裁俱乐部appMost likely you will not notice any drivability issues since this is not sensor #1. You will notice Malfunction Indicator Lamp (MIL) illumination. In some cases however, the engine may run rough.
The causes for this DTC may include:
- Contaminated or failed HO2S2 (Sensor 2)
- HO2S2 wiring/circuit problem
- Fuel pressure incorrect
- Faulty fuel injector
- Engine coolant leak
- Faulty purge solenoid valve
- PCM has failed
Diagnostic and Repair Procedures
Visually inspect the wiring and connectors for corrosion, rubbed / chafed / bent wires, wiring pins bent/loose, burnt appearance, and/or crossed wires. Repair or replace as required.
Check for exhaust leaks or other problems, repair as necessary.
总裁俱乐部appUsing a digital volt ohm meter (DVOM) set to ohms, check harness connectors for resistance. Compare to manufacturer specifications. Replace or repair as required.
总裁俱乐部appIf you have access to an advanced scan tool, use it to monitor the sensor readings as viewed by the PCM (engine running, at normal operating temperature in closed loop mode). The rear heated oxygen sensor (HO2S) normally sees a fluctuating voltage between 0 & 1 volt, for this DTC you'll likely see the voltage "stuck" at 1V. Revving the engine should cause the sensor's voltage to change (react).
The most common fixes for this DTC seem to be either an exhaust air leak, a wiring problem with the sensor/wiring, or the sensor itself. If you replace the O2 sensor, buy an OEM one (manufacturer brand) for best results.
If you remove the HO2S oxygen sensor, inspect it for contamination from fuel, engine oil, and coolant.
Other troubleshooting ideas: Use a fuel pressure tester, check the fuel pressure at the Schrader valve on the fuel rail. Compare to manufacturers specification. Inspect the purge solenoid valve. Inspect fuel injectors. Inspect coolant passages for leaks.
Related DTC Discussions
- GMC Sierra 1500 P2271 & P2273 5.3L engine
I have a 2013 GMC Sierra 1500 with 5.3l with 210,000 mi. that intermittently sets P2271 and P2273 HO2S codes ( post O2's). Have had it to the dealer and they keep saying oxygen sensors bad. Have replaced sensors twice,replaced EVAP solenoid, injectors, MAF sensor, checked for vacuum, coolant leaks ...
Need more help with a P2273 code?
If you still need help regarding the P2273 trouble code, please post your question in our FREE car repair forums.
NOTE: This information is presented for information purposes only. It is not intended as repair advice and we are not responsible for any actions you take on any vehicle. All information on this site is copyright protected.