P0139
O2 Sensor Circuit Slow Response Bank 1 Sensor 2
Generic code
Fuel and Air Metering
Medium severity
Moderate repair
Free on OBD DashX
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What P0139 means
- The fault code P0139 indicates that there is an issue with the circuit that controls the oxygen sensor for bank 1, sensor 2. This may cause the engine to run poorly or not start at all.
Possible symptoms
- Illuminated check engine light
- Poor fuel economy
- Rough idle or stalling
- Reduced engine power or acceleration
- Failed emissions test
Possible causes
- Damaged or failed oxygen sensor
- Faulty wiring or connections in the circuit
- Malfunctioning engine control module (ECM)
- Vacuum leaks
- Exhaust leaks
- Fuel pressure issues
- Malfunctioning catalytic converter
Related parts
- Oxygen Sensor: This is one of the parts that fails very commonly. It measures the amount of oxygen to ensure proper combustion. Problems in the Oxygen Sensor lead to poor fuel economy
Possible solutions
- Replace the oxygen sensor
- Check and repair any damaged wiring or connections
- Repair any vacuum leaks
- Repair any exhaust leaks
- Check and repair any fuel pressure issues
- Replace the catalytic converter if necessary
- Replace the engine control module (ECM) if necessary
Free on OBD DashX
P0139 on OBD DashX
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