It's replaced the o2 sensor after the cat. Well all I did was plug it in to test it. Computer says fuel trim for it is 99.06%. Is it just because it's plugged in and not plugged into the cat or is this o2 sensor shot?

 

Ok got the new sensor in. When I run the jeep the percentage of fuel trim for sensor 2 flashes 99.06. Is that right?

 

After cat sensors really don't affect the fuel trim. I did see one algorithm that suggested that there is a tiny bit of input from that sensor, but it's primarily the upstream (before cat) sensors that make the difference in your fuel/air.

Why did you replace this sensor? If you plan on keeping this vehicle and the sensor are all old, I generally recommend replacing all of them at the same time.

If you don't get any check engine light/codes, generally speaking you should be okay.

 

Yep! Don't worry about it unless jeepy is
Throwing you codes! They can also effect your emissions testing so don't ignore it for too long! Also you can just try un clipping the clip and spraying the electrical connector with electrical connector cleaner! It's worth a try before you replace the part! oh and they can be a ***** to get out if they are ceased sensor one normally isn't bad but sensor 2 I had to torch it to get it out on mine!

 

Yea my old sensor after cat took a crap. It was throwing a code. I replaced it going to replace sensor 1 here pretty shortly. Get all brandy new o2 sensors in this transportation device

 

I wouldn't worry about it until it gives you the bank 1 sensor 1 code, what's the point in changing something that works fine?

 

i also had to torch mine

 

i just bought my 2001 xj and there’s not a wire that goes to my o2 sensor bank 1 sensor 2 below the first cat and i was wondering where does that wire go and does it effect much

 

if theres no wire, why wonder where it goes?

 

To try to provide a somewhat useful answer to your question...

Sensor 2(there's one on the outlet end of each of the close coupled cats on a 2001) is there to monitor catalyst efficiency for the obd ll and maybe provide a bit of feedback on the mixture.
In any case if there's no wire going to it that sensors signal isn't going to the computer and at a minimum it will probably set a code and the CEL . Depending where you are located you won't pass emissions inspection.
Likely someone cut the wire off or it got torn off somehow.
You'll need to start searching for the remaining wire.