P01F6
O2 Sensor Signal Biased/Stuck Lean Bank 1 Sensor 4
Bank 1 sensor 4 O2 sensor signal is biased low — sensor stuck reading lean regardless of true mixture. A drifted or sluggish lambda sensor lets the mixture run lean or rich without correction — fuel economy and emissions suffer immediately.
Bank 1 sensor 4 O2 sensor signal is biased low — sensor stuck reading lean regardless of true mixture. A drifted or sluggish lambda sensor lets the mixture run lean or rich without correction — fuel economy and emissions suffer immediately.
Common causes
- high
Sensor aged or contaminated
One of the most commonly reported causes for this code — check this first.
Typical part cost: $90-440
See all causes + fix costs
Create a free Wrenchify account to unlock the rest for P01F6.
Unlock causesFree forever · No credit card
First things to check
- 1Confirm the code with a scan tool and check for additional related codes.
- 2Inspect the relevant sensors, wiring, and connectors for damage or corrosion.
Get the full step-by-step diagnosis
Create a free Wrenchify account to unlock the rest for P01F6.
Unlock diagnosisFree forever · No credit card
Related codes
See related trouble codes
Create a free Wrenchify account to unlock the rest for P01F6.
Unlock related codesFree forever · No credit card
Frequently asked questions
What does P01F6 mean?
P01F6 means "O2 Sensor Signal Biased/Stuck Lean Bank 1 Sensor 4". It is a generic OBD-II code that points to a fault in the fuel & air metering.
What are the most common causes of P01F6?
sensor aged or contaminated — these are the most commonly reported causes. Verify with a proper diagnosis before replacing parts, or use the Wrenchify app for a vehicle-specific diagnosis.
Can I keep driving with this code?
The vehicle is usually drivable for short distances, but the problem can worsen or affect emissions. Diagnose and repair as soon as practical. Use the Wrenchify app for a full diagnosis specific to your vehicle.
Get the full P01F6 diagnosis for your vehicle
Year, make, model + step-by-step repair help — free plan included.