O2 Sensor Heater Circuit Malfunction Bank 2 Sensor 1
The engine computer found a problem in the heater circuit for the front oxygen sensor on bank 2. That heater helps the sensor warm up quickly so the engine can control fuel mixture properly. When it fails, the engine may run richer, use more fuel, and set a check engine light.
You can usually drive short distances, but the engine may use more fuel and run less cleanly. Have it checked soon, especially if the engine runs rough or the check engine light is flashing.
P0155 indicates the powertrain control module detected a malfunction in the heater circuit of the upstream oxygen sensor on bank 2, sensor 1. The fault may be an open circuit, short, blown fuse, failed heater element, damaged wiring, or poor electrical connection. Because the heater is needed for fast sensor warm-up, the code can affect closed-loop fuel control and emissions.
It is the upstream oxygen sensor on the side of the engine that does not contain cylinder 1.
Yes. If the heater does not work, the engine may stay in warm-up fuel settings longer and use more fuel.
Often yes, but wiring, connectors, and fuse problems are also common and should be checked first.
No. The code will usually return until the heater circuit problem is repaired.