P102D 2016 Toyota RAV4 Code - O2 Sensor Heater Circuit Performance Bank 1 Sensor 2 Stuck ON

P102D indicates an issue with the oxygen (O2) sensor heater circuit for Bank 1 Sensor 2, specifically that it is stuck in the "ON" position.

Common symptoms include an illuminated check engine light, reduced fuel efficiency, poor engine performance, and difficulty passing emissions tests.

The code can be caused by a malfunctioning O2 sensor, a shorted or damaged heater circuit, faulty wiring or connectors, or an issue with the engine control module (ECM).

Bank 1 Sensor 2 is the downstream oxygen sensor located after the catalytic converter on the same side as cylinder 1.

While the vehicle may still be drivable, ignoring this code can lead to reduced fuel efficiency, increased emissions, and potential damage to the catalytic converter over time.

Diagnosis involves using an OBDII scanner to confirm the code, visually inspecting wiring and connectors, testing the O2 sensor heater circuit for continuity, and checking for short circuits.

Repairs may include replacing the faulty O2 sensor, repairing or replacing damaged wiring or connectors, or reprogramming or replacing the ECM if necessary.

The cost depends on the repair. Replacing an O2 sensor typically costs $150–$400, while wiring repairs or ECM replacement can vary significantly.

You may need an OBDII scanner, a multimeter to test the circuit, basic hand tools, and possibly a specialized oxygen sensor socket.

Yes, a malfunctioning O2 sensor can lead to improper air-fuel mixture, which may damage the catalytic converter and reduce engine efficiency over time.