From Ross-Tech Wiki

16558/P0174 - System Too Lean, Bank 2

Possible Symptoms

  • Irregular behaviour

Possible Causes

  • Fuel system
  • Excessive fuel pressure
  • Leaking or contaminated fuel injectors
  • Leaking fuel pressure regulator
  • Low fuel pressure or running out of fuel
  • Vapor recovery system
  • Air leaks after the MAF
  • Vacuum leaks
  • Improper seated engine oil dipstick
  • Stuck EGR valve
  • Oil overfill
  • Cam timing
  • Cylinder compression
  • Exhaust leaks before or near HO2Ss.

Special Notes

Also see: Fuel Trim Info