OBD-II code guide

P0150 Oxygen Sensor Circuit Bank 2 Sensor 1

P0150 means the upstream oxygen sensor circuit on bank 2 is not behaving as expected.

What it means

The bank 2 upstream oxygen sensor signal may be unreliable for fuel control.

Common symptoms

  • Check engine light
  • Poor fuel economy
  • Rough idle
  • Hesitation
  • Emissions failure

Likely causes

  • Oxygen sensor fault
  • Wiring issue
  • Exhaust leak
  • Rich or lean mixture
  • Connector contamination

First checks

  • Confirm bank 2 location.
  • Inspect wiring near the exhaust.
  • Review fuel trims by bank.
  • Check for exhaust leaks before replacement.