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02 Subaru Legacy oxygen sensor monitor
Posted to Emissions Forum on 4/11/2017 8 Replies

Hello, I'm working on an 2002 Subaru Legacy and attempting to set the oxygen sensor monitor. So far I have replace the front air/fuel with a Denzo and have driven the vehicle over 400 miles and the oxygen sensor monitor will not complete it's test. Because we "felt" an ever so slight misfire, we tried a fuel injection service and the perceived misfire is gone. 100 miles later, still won't set. Drove the vehicle per tip I found online, "from a cold start, accelerate to 60 mph for 5 mins and decelerate to a near stop without touching the brakes and accelerate to 60 mph for another 5 mins". Tried this a few times at 2:00am on the I-5 and nothing. In desperation, I connected the two green check connectors, nothing. I also disconnected the battery and touched the cables together and all the other monitors set quickly, except the oxygen sensor.

Any tips you'd like to share? Or give a direction for further diagnostics. I examine mode 6 and all the Pid values appear to be within spec according to Alldata information.

Thank you for your time.

Dwight Bresemann
LSI Automotive
Oceanside, California, USA

8 Replies Received (View Replies)


car Vehicle Data

2002 Subaru Legacy L 2.5L

Engine2.5 L
Trans4-speed Automatic (Electronic)