P0155 2010 Ford Fusion Code - O2 Heater Circuit Bank 2 Sensor 1

P0155 indicates a malfunction in the oxygen sensor heater circuit for Bank 2 Sensor 1, which is responsible for heating the O2 sensor to ensure accurate readings.

Common symptoms include an illuminated check engine light, reduced fuel efficiency, increased emissions, and possibly rough idling or poor engine performance.

Bank 2 refers to the side of the engine opposite the cylinder with the #1 spark plug. Sensor 1 is the upstream oxygen sensor located before the catalytic converter.

Possible causes include a faulty oxygen sensor, damaged wiring or connectors in the heater circuit, a blown fuse, or a malfunctioning powertrain control module (PCM).

While the car may still be drivable, prolonged operation with this code can lead to reduced fuel efficiency and increased emissions. It’s best to address the issue promptly.

Repairs may include replacing the O2 sensor, repairing damaged wiring or connectors, checking and replacing a blown fuse, or, in rare cases, reprogramming or replacing the PCM.

Diagnose by inspecting the wiring and connectors near the Bank 2 Sensor 1, testing the O2 sensor's resistance, checking for a blown fuse, and using a scan tool to monitor live data.

Replacing an oxygen sensor typically costs $150-$300, including parts and labor. Additional repairs, like fixing wiring issues, may vary in cost.

Yes, a faulty O2 sensor can cause poor fuel-air mixture readings, leading to reduced engine performance, rough idling, and increased fuel consumption.

Regularly inspect and maintain the oxygen sensor and wiring, avoid using low-quality fuel, and ensure timely engine tune-ups to prevent future issues.