Manufacturer-specific code

This code means different things on different makes. Find yours below.

• Ford

  Lack of upstream oxygen sensor switching: sensor indicates rich (bank 1)

  The front oxygen sensor stays rich and does not switch, even though fuel control is taking fuel away.

  Likely causes, most likely first

  1. 01Leaking injector
  2. 02Fuel pressure too high
  3. 03Oil diluted with fuel from many short trips
  4. 04Oxygen sensor contaminated by coolant or oil
  5. 05MAF sensor reading too high

  Severity: Caution: get it checked soon · DIY with tools and some experience