2000 Merc. Mountaineeer o2 sensor location

I have a 2000 mountaineer 5.0 v8 and the drivers side upstream o2 is bad and i have no idea where it is. i have taken the tire and wheel well off and i cant find it. can someone help me? thanks

Got search?

It works wonders

i just did search and i couldnt find anything. do you know the sensor is at? ive seen people say take the wheel off and its there but i didnt see it.

Bank 1 is the side of the engine with the number one cylinder. For the 5.0 Liter Ford Engine this means the passenger side, sensor 1 means that it is the first sensor that the exhaust reaches as it exits the engine and travels rearward toward the back end, it is between the catalytic converter and the engine exhaust manifold/header. you've already jacked up the truck and taken the wheel off, support the truck with a jack stand and crawl under there. Its not a tiny sensor, you will see it. start by checking the electrical connection of the sensor, try to wiggle it, pull it apart put it back together what have you. Then clear the code by either disconnecting the battery for a while, or using a scan tool. that may do the trick for you. good luck

Edit: by the way, it is screwed into the exhaust pipe, not the engine, not the car body, it's not the egr tube which is on top of the exhaust manifold in the engine bay, get under the truck safely, It is not hiding from you although it's not right out in the open where it can be damaged by every little piece of road debris, so it might be hard to get a wrench on it to turn it out.

its the drivers side sensor and the only sensors i found where in the exhaust pipe and no matter who i ask i get different answers. i took the battery cables off and im letting them sit for a while. whoever invented o2 sensors is cleaning up

rrzany said:

its the drivers side sensor and the only sensors i found where in the exhaust pipe and no matter who i ask i get different answers. i took the battery cables off and im letting them sit for a while. whoever invented o2 sensors is cleaning up

Click to expand...

those sensors in the exhaust pipe are the oxygen sensors

rrzany said:

. whoever invented o2 sensors is cleaning up

Click to expand...

You're right about that
http://www.bosch.com.au/content/language1/html/4566.htm

yea i know. those are the only ones that i could find. its the upstream ones i cant find.

the upstream sensor is the one that is after the exhaust header and before the cat converter.

Dude
the driver side (bank 2) sensor 1 ( upstream) is right under the dang transmission to engine mating point. You probably bumped your head on it.


The remaining 3- 02 sensors are all on the passenger side of the transmission.

so they are not in the manifold but in the pipe because the ones in the pipe (close to engine) are the ones i changed. so the downstream are down towards the end of the exhaust? me and my old man both crawled under and only saw the two previously mentioned.