OBD-II code · Powertrain (generic)

P0145 O2 Sensor Circuit High Voltage (Bank 1 Sensor 3)

The ECU detects an abnormally high voltage from the third O2 sensor on bank 1. Indicates persistently rich exhaust, a shorted sensor or wiring shorted to a voltage source.

Is it safe to drive with P0145?

Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.

Common causes

  • Most likelyRich exhaust (leaking injector, high fuel pressure)
  • PossibleSignal wire shorted to voltage
  • PossibleO2 sensor failed

Symptoms

  • Check engine light on
  • Increased fuel consumption
  • Possible rough idle or hesitation
  • Failed emissions test

Repair at a glance

Difficulty
Easy
DIY friendly
Often, with basic tools
Typical labour
0.3–1.5 h
Emissions test
Likely to fail
After the fix
A drive cycle is needed before the light stays off
Parts involved
Oxygen Sensor B1s3, Oxygen Sensor Wiring

Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.