O2 Sensor Signal Stuck Lean (Bank 2 Sensor 1)

What it means

This code is the same as P2195 but for the upstream oxygen sensor on bank 2, the side of the engine that does not contain cylinder 1. The engine computer has found that the sensor keeps reporting lean and does not respond to added fuel, either because that bank really runs lean or because the sensor is faulty.

Related codes: P2195P2198P0151P0174P0153

Symptoms4

• Check engine light on.
• Higher fuel consumption.
• Occasional stumbling or slight loss of power.
• Failed emissions test.

Possible causes5

• Aged or contaminated bank 2 upstream oxygen sensor.
• Bank 2 exhaust manifold leak ahead of the sensor.
• Air leak near the bank 2 side of the intake manifold or vacuum hoses.
• Sensor wiring or heater circuit fault.
• A shared cause such as low fuel delivery if P2195 is also stored.

How to diagnose5

1. Read all stored codes; P0174 or P2195 alongside it suggests a real lean condition or a shared cause.
2. Compare the bank 2 sensor signal and fuel trims with bank 1.
3. Test the sensor's response to added fuel with propane enrichment or a scan tool command.
4. Inspect the bank 2 exhaust manifold for leaks ahead of the sensor.
5. Inspect the sensor wiring, connector and heater circuit.

How to fix5

1. Repair the exhaust leak or air leak on the bank 2 side.
2. Repair the sensor wiring or connector.
3. Fix a lean condition in the fuel system if it affects both banks.
4. Replace the bank 2 upstream oxygen sensor if it does not respond to added fuel.
5. Clear the codes and confirm the sensor responds normally.

Repair cost

In Saudi riyals; the highlighted part is the expected range for this fault.

The cost is low for a leak or wiring repair, and rises to the price of a new sensor; labor increases if the sensor is hard to reach.

Prices are rough estimates for common cars at independent workshops and vary with the car and the source of the part.
Prices last updated: September 2026

Frequently asked questions