P0162
O2 Sensor Circuit Malfunction (Bank 2, Sensor 3)
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P0162 indicates a general circuit malfunction in the third oxygen sensor on Bank 2. Sensor 3 is found only on vehicles with multiple catalytic converters per bank — typically larger V6 or V8 engines with dual-stage catalytic converter systems. This sensor sits downstream of a secondary catalytic converter and monitors its efficiency.
Because this sensor is positioned furthest downstream in the exhaust system, it has the least impact on engine performance and fuel management. Its primary purpose is emissions monitoring of the secondary catalytic converter. Most drivers will not notice any driveability changes, though fuel economy may suffer marginally if the PCM adjusts fuel trims in response to the missing or faulty data.
If your vehicle has set this code, verify that the sensor connector is securely attached and inspect the wiring for heat or physical damage. Sensor 3 is often located in a harder-to-reach position than Sensors 1 and 2, so the repair may be slightly more involved. The sensor itself is the most likely culprit and replacement is the standard fix.
Severity
Symptoms
- •Check Engine Light is on
- •Slightly decreased fuel economy
- •Mild exhaust odor changes
- •Possible minor rough idle
- •Failed emissions inspection
- •No significant driveability issues in most cases
Likely Causes
The third O2 sensor on Bank 2, typically located after a secondary catalytic converter, has failed or degraded and is no longer providing reliable readings.
The wiring harness or connector for this sensor has been damaged by heat, corrosion, or physical impact, disrupting the sensor signal.
An exhaust leak at or near the sensor mounting point allows ambient air to interfere with accurate exhaust gas readings.
The secondary catalytic converter that this sensor monitors has failed, producing exhaust gas readings that fall outside expected parameters.
A fault in the PCM's ability to read or process the signal from this particular sensor circuit.
Estimated Cost
Professional Repair
Includes parts + labor
Common Fixes
- Replace the Bank 2 Sensor 3 oxygen sensor
- Repair or replace damaged wiring and connectors
- Fix exhaust leaks near the sensor location
- Inspect secondary catalytic converter for failure