Ok... so i have a 1994 cherokee 4.0 litter high output, and i need to know where the sensors are.. pictures would help.. what i need for the job, etc. Thanks in advance!

 

bump...

 

It is raining here so sorry no pick. But just fallow your exost from the header and at one or two locations (depending on what year). Wires will come out. Don't buy new. Pull them out and spray them with brake clean shake and repeat. The 4.0 is a dirty running motor and coats the 02's with carbon. Clean the carbon off the BB in the sensor and it will get a good reading.

 

I got a '94 and I can tell you that it has just one stock, upstream from cat, right below where the manifold connects to the pipe. Easily found from underneath vehicle. NTK is the only suggested replacement, as they are original equipment.

 

What do you think about cleaning the original one like brutalxj suggested?

 

Cleaning it is fine if that's all it needs. But if it's bad no amount of cleaning will help it.

 

90% of the time cleaning O2 sensor does not work if the sensor has over hundred thousand miles just replaced it

 

How do i find out if i need 2 or 4 sensors? (cali or exc cali) and what are the part numbers because i have no idea what the difference is between 1, 2, 3, 4 wires means. sorry if this is a really easy question. i been looking around and still am not sure what to look for.

 

How do i find out if i need 2 or 4 sensors? (cali or exc cali) and what are the part numbers because i have no idea what the difference is between 1, 2, 3, 4 wires means. sorry if this is a really easy question. i been looking around and still am not sure what to look for.

 

I'm not sure where they would be on your 94 but I know on my 97 there is a downstream one right on the cat.

 

Look for a sticker on your firewall driver's side. If its California emissions (two "upstream" or pre-cat and two "downstream" or post-cat sensors), it'll say on the sticker. If not its just one each.

Alternatively crawl under driver side door and look for two football shaped catalytic converters coming off of your exhaust manifold. If you have them then you're California emissions.

Then go to rockauto.com and order NTK brand. It's way cheaper than the auto parts store.

 

ah ok thank! im pretty sure im not cali, so would you happen to know part #'s? or how many wires. its a 2001 XJ

 

Ok hijacker, I put this info out there so that it would be easily searchable. But I'll link it anyway.
If you have a 2001 then you have Cali emissions standard with 4 O2 sensors. And I'll even include a picture for free!

https://www.cherokeeforum.com/f2/200...ations-162445/

 

Awesome thank u sir