How many upstream oxygen sensors are there? I thought there were 2, but i dont see the other one??? Are there 3 total?? 2 upstream and 1 downstream??? On oxygensensors.com it says 2 are required for upstream?? Help please! If there is a second upstream sensor can someone post pics of the locations? Im cornfused.:attention

 

yea there are 3 total. The other one is on ur cat convertor.

 

Isnt the one on the cat the downstream?

 

1 on each side of the y-pipe and 1 on the cat. I replaced all 3. I didn't have any problems finding them. The only one that was a little harder to get to was the one on the firewall side but if you get under there and look up, you'll see it.

 

Thanks.. I guess I just wasnt looking hard enough.. Well I cant manage to get a wrench up there (too long) as someone had suggested might work, so ill just have to get the 02 sensor socket for a ratchet tomorrow.

 

Thats what I used. It only costs like $8. It's still a little tight but you should be able to fit it up in there without too much trouble.

 

Cool, I have a ratchet with an adjustable head so that may help i think.. $8? Everyone I talk to says its more like $15?

 

You can rent it for free at Autozone.

 

You could do that also. I don't know if you have an AID auto near you but that's where I got mine for $8.

 

Done! I dont notice a difference in performace, maybe very slightly more smooth, but that might just be the placebo affect? Had to buy the 02 sensor socket and it went smoothly. Fishing the front sensor down the right path through the engine bay to the exhaust was a pain sorta.. But at least i have peace of mind. The old sensors didnt even look that bad.. Not redish in color, just slightly chared.