1. Attachments are working again! Check out this thread for more details and to report any other bugs.

fuel air ratio sensor

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by condor, Apr 13, 2011.

  1. condor

    condor New Member

    Joined:
    Jun 17, 2007
    2
    0
    0
    Please advise how to replace the "upstream" fuel air ratio sensor in a 2005 Prius. Photos or directions to a You Tube site would be helpful. Thanks!
     
  2. twittel

    twittel Senior Member

    Joined:
    Jul 7, 2010
    1,605
    148
    0
    Location:
    Mt. Pleasant, SC
    Vehicle:
    2010 Prius
    Model:
    III
    I found these two PriusChat posts doing a quick Yahoo search. I think this is what you're asking. You can do your own YouTube, photo search. It's easy:

    1. Mounted on the front of the throttle body, just below the air cleaner. If you take the air filter out, and look down the throttle body throat, you'll see the MAF sensor poking in from the front. It's held on by two screws, located in the perfect position to prohibit use of normal-sized screwdrivers for easy removal. Many others recommend just buying a spray can of MAF sensor cleaner and spraying it from the top, without removing it

    2. Remove the sensor and carefully wiped it with a soft toothbrush and isopropyl alcohol...
     
  3. Patrick Wong

    Patrick Wong DIY Enthusiast

    Joined:
    Mar 8, 2008
    18,200
    6,482
    0
    Location:
    Green Valley, AZ
    Vehicle:
    2015 Prius
    Model:
    Two
    I believe the OP wants to replace the air/fuel ratio sensor which is located in the exhaust system, upstream from the catalytic converter. Another poster recently commented on this as well as the need to machine the oxygen sensor socket to fit into the available space. I recommend the OP do a Prius Chat search.

    It will also probably be necessary to remove some passenger cabin trim in order to access the A/F ratio sensor's wiring harness connector located inside the vehicle.

    If all else fails, the Toyota repair manual documentation can be accessed at techinfo.toyota.com which is a subscription website.
     
  4. seilerts

    seilerts Battery Curmudgeon

    Joined:
    Mar 7, 2010
    3,326
    1,513
    38
    Location:
    Santa Fe, NM
    Vehicle:
    2005 Prius
    1 person likes this.
  5. prius4ed

    prius4ed Member

    Joined:
    May 13, 2008
    120
    4
    0
    Location:
    Irvine, CA
    Vehicle:
    2004 Prius
    fuel air ratio sensor - pricing and part sources? Dealer Warranty?

    Anyone know where to buy this part and have they tried it on their car? Ebay sells them, but not sure they'll work right.

    What's the warranty on these from Toyota (Calif)? I think they're part of the emissions system, but not sure if they're covered for as long as the rest of the emissions system.