can't find my after cat O2 sensor E350 van
#16
#17
I have a 1998 ford e350 5.4L extended van with 140,000 miles. The check engine light is on and it just failed emmisions test, I am guessing that the O2 sensors are bad. I figure with that much milage I should change them anyways. I replaced the 2 before the cat ( thats closest to the engine ) with Bosh#15716 . But I can't find the O2 sensor after the cat. The service manual shows one sensor just after the cat before the muffler on the top of the pipe , but it's not there, no wire either.
I read some place that some models don't test the emissions after the cat but that's not what my service manual shows.
Does anyone have any more info on this ?
Thanks for your help !
I read some place that some models don't test the emissions after the cat but that's not what my service manual shows.
Does anyone have any more info on this ?
Thanks for your help !
#18
#19
Join Date: Oct 2002
Location: St. Louis (Out in the woods)
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I believe it depends on the vehicle GVWR, over 8500# has a different emission system and doesn't require post-cat sensors.
Vehicles > 8500 GVWR AND with "Federal" emissions did not have downstream O2 sensors as they were calibrated to only OBD1 standards. Vehicles > 8500 with "California" or "OBDII" emissions had downstream O2 sensors (and more).