Passenger side could mean drivers side, depending what country you are in or what country the code list is from, put the old one back in and do the other side, see what happens.

Chers George

 

Check the connector and make sure the insides are clean and the pins are not damaged. Ensure that the connectors are firmly latched to each other. Other possibilities could be damaged wiring, the o2 sensor itself, or even a malfunctioning ECM.

 

Hi Olrac - I just went through this with my 2002 Bean. I also installed on the passenger side, but later found out that BANK 2 is on the Driver side (Left Hand side) on the USA Subaru cars. I also found a link where you can download a Service Manual supplement for the H6 engines with a lot of info on ECM codes and what to do.

http://www.subaru-car.ru/leg1/leg1_sec1_11-2.pdf

With directions from above document, I measured resistance on the Sensor heater pins and confirmed that it was the driver side that was causing the P0051 code. So I put the (still good) sensor I'd taken out of the passenger side into the driver side, cleared the code, and all is good.

 

Sometimes the error code doesn't mean exactly what it says... So just because the oxygen sensor reading is outside the adjustment range of the fuel/air mixture, doesn't necessarily mean the oxygen sensor is bad.

I recently had an O2 sensor error on an old Toyota Camry, and the problem was that the rubber vacuum line to the MAP sensor had a crack in it. So replacing a $0.10 piece of tubing fixed that problem. (After I had already replaced the oxygen sensor, of course...)

The O2 sensor error usually means the computer can't adjust the mixture enough to make the O2 sensor produce the expected output. So if it's not the O2 sensor, the check other things that also affect the mixture. (Vacuum leaks, pressure sensors, flow sensors, etc.)

Good hunting...

 

P0051

Im getting this code on my '04 LL Bean outback (6 cyl) but I can't even find the oxygen sensor on the left side. Does anyone have a photo of where it is located and what it looks likes?

Thanks

 

Have you taken the bottom engine cover off?

They are easy to spot on my '03 from the bottom.

 

Here ya go. Ignore the extra holes. They are there on purpose.

 

Thanks

I was able to see it no problem after removing the bottom cover. Got a new sensor from Amazon for $84 (AC) and it took less than 10 minutes to replace, clear the code and get my state inspection!