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02 Sensor help!

Posted: Thu Feb 04, 2016 10:56 pm
by craig1980
Looking for some advice on replacing both 02 sensors in my 03 pathfinder. Any tips? Can they be removed in place? Looks like there are coolant hoses on both sides that need to be removed but access still seems almost impossible. Has anyone done these? Please help!

Posted: Sun Feb 07, 2016 5:43 pm
by craig1980
Anybody????

Posted: Sun Feb 07, 2016 9:50 pm
by smj999smj
Been so long since I've done one that I can't remember! Have you tried looking up from underneath the vehicle? On the R51's, you get them through the wheel well, but I don't think you have access on the R50.

Posted: Thu Feb 11, 2016 10:43 am
by craig1980
Sadly there is no access from underneath or the fender wells. Its freezing in NY but next week where back to 40 degrees. I have some ideas to try. will see what happens I guess.

Posted: Sat Feb 20, 2016 12:25 pm
by craig1980
A little disappointed I didn't get any help, so I figured my reply may help someone in the future. I was able to use a standard 7/8" 02 sensor socket (the one with the slit cut out). The one that looks like a crow foot could not get deep enough given the heat shield is in the way. I borrowed a set of three from Advance Auto. They had a set as part of their loaner tool. Anyway, I have been spraying PB Blaster on both sensors for about a week. A long vacuum hose will help get the PB down there because there is no way to fit the can in such a small space. I have driven the vehicle here and there in between, but I always sprayed it at night. I started out on the driver side. I was able to move the coolant hose to the side and snake my hand and attach the socket with a 3/8 drive craftsman universal joint. I then attached a long extension to it with a 3/8 drive ratchet. It came out very easy. I was able to hand thread the new one in and then torque it to 30 FT. LBS. I did the exact same thing for the passenger side but access is extremely tight. I have a fairly small hand so besides getting bruised from squeezing my hand in and out it went well. A couple of side notes:
The driver side has an inaccessible zip tie that holds the wire. I simply cut the wire and pulled the remaining wire out. No need to connect it again. I used NTK sensors. I bought them on Ebay for around $34 shipped. They both were exactly what Nissan used from the factory. Same brand and everything. No coolant hoses needed to come off so no need to refill and bleed the system. If you get a different 02 sensor socket make sure it is thin wall. The original one I had was twice as thick and had trouble fitting on.