The resistance of the heater circuit in bank 1 is too low to heat fuel until it achieves air to fuel ratio of 14:7. The problem is coming from the 1st sensor of bank 1. This code is usually triggered when resistance level is below 0.8A.
- Short or open in the O2 heater circuit
- Defective O2 sensor heater
- There’s a wiring problem in the circuit leading to the heater. It may be broken or frayed
- Defective ECM (this is the least likely cause)
- Inspect wiring and power to the O2 sensor and ensure there’s no damage/open/short
- Use code reader to pull engine codes