2005 TOYOTA COROLLA CHECK ENGINE LIGHT IS ON

  • Tiny
  • Mrronald
  • 2005 TOYOTA COROLLA

Engine Performance problem
2005 Toyota Corolla 4 cyl Front Wheel Drive Automatic 77000 miles

scan code is P0171 - system too lean. What does that mean? Do I need to replace the O2 sensor, or is it something else?

Do you
have the same problem?
Yes
No
Thursday, January 14th, 2010 AT 9:38 AM

1 Reply

  • Tiny
  • Mmprince4000
  • EXPERT
  • 8,715 POSTS

The upstream O2 sensor is reading a lean fuel mixture, this could be an O2 sensor, clogged injector, low fuel pressure.

I would replace the O2 sensor, erase code. If code reappears, then measure fuel pressure with mechanical gauge to start.

I would also add a can of SeaFoam after changing O2 sensor to gas tank.

Was this
answer
helpful?
Yes
No
Friday, January 15th, 2010 AT 10:06 AM

Please login or register to post a reply.

Other Check Engine Soon Light Questions