P014F

What it means

P014F means the engine control unit has detected that the upstream oxygen (air-fuel ratio) sensor on bank 2, sensor 1 is responding too slowly when the mixture changes from lean to rich. The sensor signal takes longer than expected to follow the change, which suggests the sensor is ageing or contaminated, or that something is distorting its readings. Bank 2 is the side of the engine that does not contain cylinder number 1.

Symptoms

• Malfunction indicator lamp on
• Slightly higher fuel consumption
• Rough or unstable idle in some cases
• Reduced performance or hesitation under load
• Failed emissions test
• Fuel trims drifting away from normal on bank 2

Possible causes

• Ageing, worn or contaminated bank 2 sensor 1 (slow to react)likely
• Damaged wiring, poor connector contact or corrosion in the sensor circuitpossible
• Exhaust leak upstream of or near the sensor letting in false airpossible
• Sensor heater circuit fault or heater performance reduced, so the sensor runs too coolpossible
• Contamination from oil, coolant or silicone sealant, or from fuel additives, coating the sensorpossible
• Underlying fuel or air metering fault on bank 2, such as a leaking injector or vacuum leak, upsetting the mixturerare
• Fault in the engine control unit sensor inputrare

How to diagnose

1. Read all stored and pending codes and the freeze frame data, noting engine temperature, load and fuel trim values when the fault set
2. Check for related codes such as heater circuit, other oxygen sensor or misfire codes, and deal with those first
3. Inspect the bank 2 sensor 1 wiring and connector for chafing, heat damage, water ingress and corrosion
4. Look and listen for exhaust leaks around the manifold, flexible joints and the sensor mounting
5. View live data for bank 2 sensor 1 and compare its switching speed and fuel trims with bank 1 at idle and steady speed
6. Check short and long term fuel trims on both banks to spot a vacuum leak, injector fault or fuel pressure problem
7. Check the sensor heater resistance and supply against the manufacturer's specification, as the procedure varies by model and sensor type
8. Remove the sensor and inspect it for soot, oil or coolant contamination if the readings point to it

How to fix

• Replace the bank 2 sensor 1 with a correct specification sensor if it is confirmed slow or contaminated
• Repair or replace damaged wiring and connectors in the sensor circuit
• Repair any exhaust leak near the sensor and renew faulty gaskets or joints
• Repair the cause of any contamination, such as oil burning or a coolant leak, before fitting a new sensor
• Correct any vacuum leak, injector or fuel supply fault found on bank 2
• Clear the codes after repair and road test to confirm the fault does not return

Can I keep driving?

Nearby codes

• P014EGenericO2 Sensor Slow Response - Rich to Lean Bank 2 Sensor 1
• P0150GenericO2 Sensor Circuit Bank 2 Sensor 1