Volvo AWD 850 Forum

INDEX FOR 10/2025(CURRENT) INDEX FOR 4/2004 850 INDEX

[<<]  [>>]


THREADED THREADED EXPANDED FLAT PRINT ALL
MESSAGES IN THIS THREAD




  REPLY TO THIS MESSAGE    PRINT   SAVE 

O2 Sensor Fault 850 1994

posted by  someone claiming to be chuck on  Wed Dec 4 12:15 CST 2002 [RELATED]

A2 fault codes 435 and 436 keep comming up. I reset them and about two days later they reappear. Problem started after having the battery disconnected for about three hours while doing a transmission pnp switch replacement. I've checked all vaccuum hoses for leaks. All ok.

I've read in the archives that disconnecting your battery for an hour resets the fuel addaptives. Could this be my problem and if so will the long term fuel adaptives over time adjust to the point where I will not get these fault codes?

Thanks








  •   REPLY TO THIS MESSAGE    PRINT   SAVE 

    O2 Sensor Fault 850 1994

    posted by  someone claiming to be Karl on  Thu Dec 5 00:34 CST 2002 [RELATED]

    It's most likely that those two codes are really caused by a vacuum hose leak, not O2 sensors. Carefully inspect the vacuum hoses by the intake manifold behind the PS pump (if turbo) and at its other end where it's routed to the air intake hose opposite a sensor, lower area where the intake hose attaches to the turbo. If not turbo, remove the plastic throttle body cover and check at the vacuum T and check the flame trap hoses.







<< < > >>



©Jarrod Stenberg 1997-2022. All material except where indicated.


All participants agree to these terms.

Brickboard.com is not affiliated with nor sponsored by AB Volvo, Volvo Car Corporation, Volvo Cars of North America, Inc. or Ford Motor Company. Brickboard.com is a Volvo owner/enthusiast site, similar to a club, and does not intend to pose as an official Volvo site. The official Volvo site can be found here.