P2A06

O2 Sensor Circuit Range/Performance Bank 1 Sensor 4

Moderate severity

The fourth oxygen sensor on bank 1, where present, returns implausible values during long-term plausibility evaluation. Used on multi-stage aftertreatment systems.

Common causes

Sensor aging
One of the most commonly reported causes for this code — check this first.
high
Typical part cost: $130-550
Sensor element aged beyond calibration window
Less common, but worth ruling out after the more likely causes.
low
Typical part cost: $130-550
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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.

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Related codes

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Frequently asked questions

What does P2A06 mean?

P2A06 means "O2 Sensor Circuit Range/Performance Bank 1 Sensor 4". It is a generic OBD-II code that points to a fault in the auxiliary emission controls.

What are the most common causes of P2A06?

sensor aging; sensor element aged beyond calibration window; sensor mounting loose - signal damping — 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.

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