Faulty downstream oxygen sensor (Bank 2 Sensor 3) due to contamination or age; Damaged or corroded wiring or connector at the sensor or along the circuit; Exhaust leak before the sensor, allowing outside air to affect the reading; Failed oxygen sensor heater circuit within the sensor; Poor electrical connection at the ECM or a chafed wire harness; Contamination from engine oil or coolant entering the exhaust stream

DTC codes / P01xx · Fuel and air metering / P0162

P0162O2 Sensor Circuit (Bank 2 Sensor 3)

Q: What does code P0162 mean?

O2 Sensor Circuit (Bank 2 Sensor 3). P0162 indicates that the engine control module (ECM) has detected an abnormal voltage condition on the oxygen sensor circuit for Bank 2 Sensor 3, which is the downstream sensor located after the catalytic converter on the bank of cylinders that does not contain cylinder number one. The ECM monitors this circuit for voltage that stays outside the expected range for too long, which typically points to a wiring fault, a failed sensor, or an exhaust leak rather than a catalytic converter problem.

P0162 indicates that the engine control module (ECM) has detected an abnormal voltage condition on the oxygen sensor circuit for Bank 2 Sensor 3, which is the downstream sensor located after the catalytic converter on the bank of cylinders that does not contain cylinder number one. The ECM monitors this circuit for voltage that stays outside the expected range for too long, which typically points to a wiring fault, a failed sensor, or an exhaust leak rather than a catalytic converter problem.

SystemPowertrain

Code typeGeneric (all makes)

SeverityLow

Fix difficultyIntermediate

AreaFuel and air metering

Symptoms you may notice

Illumination of the check engine light, often with no other noticeable symptoms
A slight decrease in fuel economy as the ECM may default to a richer fuel mixture
Occasional rough idle or hesitation during acceleration if the sensor signal is erratic
A faint sulfur or rotten egg smell from the exhaust in some cases
Failed emissions inspection due to the stored trouble code

Common causes, most likely first

Faulty downstream oxygen sensor (Bank 2 Sensor 3) due to contamination or age
Damaged or corroded wiring or connector at the sensor or along the circuit
Exhaust leak before the sensor, allowing outside air to affect the reading
Failed oxygen sensor heater circuit within the sensor
Poor electrical connection at the ECM or a chafed wire harness
Contamination from engine oil or coolant entering the exhaust stream

How to diagnose and fix it

Perform a visual inspection of the Bank 2 Sensor 3 wiring and connector for damage, corrosion, or loose pins
Check for exhaust leaks around the sensor bung and upstream exhaust components using a smoke test or listening for ticking
Measure the sensor heater resistance and compare to specifications to rule out a failed heater element
Backprobe the sensor signal wire and observe voltage with a scan tool to see if it switches properly when the engine is at operating temperature
Inspect the ECM connector and harness for continuity and shorts to ground or power
Replace the Bank 2 Sensor 3 oxygen sensor if electrical tests confirm it is faulty
Clear the code and perform a drive cycle to verify the repair and ensure the monitor completes

What P0162 really tells you about the sensor

A P0162 code often sets because the downstream sensor is simply worn out and slow to respond, not because the catalytic converter has failed, so avoid replacing the converter before testing the sensor circuit.
Exhaust leaks upstream of the sensor can cause a lean false reading that mimics a sensor failure, so always check for leaks before condemning the sensor.
The downstream sensor on Bank 2 is sometimes harder to access, leading technicians to skip thorough circuit testing and replace the sensor unnecessarily.
Oil or coolant contamination from internal engine leaks can foul the sensor and set this code, so addressing the root cause is essential to prevent repeat failures.
On some vehicles, a weak battery or charging system issue can cause erratic sensor voltages and set this code, so check the charging system as part of diagnosis.

Can I keep driving with P0162?

You can generally continue driving with P0162 because the downstream sensor mainly monitors catalytic converter efficiency and does not affect engine operation significantly. However, avoid prolonged driving with the check engine light on, as it may mask other emerging issues, and schedule diagnosis soon to maintain emissions compliance.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.