Since buying my Jeep I have had issues with my O2 sensor.
We had to replace it every 2 weeks so I finally unplugged
it for the Jeep to drive normal.
It irritates me thinking about it that parts on my Jeep aren't working so I want
to find a permanent fix to this.

I went to a mechanic today who told me to get rid of the CAT
This just doesn't seem right to me.
Car parts should work well together if they are mounted in the same car right ?
And how is the CAT really related to the O2 sensor ?
I thought the CAT was only meant to filter out the CO2 coming from out the
exhaust.

I also looked at some forums and read that an XJ has more than just one O2
sensor.

This frustrates me even more.
With this could anyone please tell me what I'm supposed to do ?


PS: My engine light won't turn off either ad we've already tried using one of those scanners.

 

The catalytic converter does not filter anything. It is a catalyst which means it causes a reaction. The cat is made of steel and precious metals. A honeycomb of this say, platinum, is inside and the cats job is to heat up to a very high temperature and burn off the remaining unburnt hydrocarbons left in the exhaust rather than pumping them into the atmosphere. The job of the downstream o2 sensor is to read how many hydrocarbons are left in the exhaust as compared to how many the upstream o2 recorded and adjust the fuel/air mix accordingly. It so tells he PCM when the exhaust is far too rich or far too lean and tells the computer to throw a check engine because something is wrong with the fuel air mix. Now you can go with out a cat as long as you put the o2 sensor back unto The exhaust system down stream of the first one. Your cat may be bad and could be cooking the o2 sensor that is in it or covering the sensor with lots of soot causing it not to read. Your check engine light is on because something is wrong and I till the system is back in Balance it won't go off. What codes is the code checker spitting at you?

 

Don't remove the cat. Fix it properly. The light won't go off if you have the sensor unplugged. What is the code? Is it the sensor before or after the cat that you are having problems with?

 

What type of 02 sensor did you replace with? Universal or NTK?
If not OEM then go here.
http://www.ngksparkplugs.com/part_fi...uv/default.asp
Enter your info and it will give you the NTK sensor part numbers.
Then find them on Amazon for great prices..
It's The only way your XJ will be happy..

 

Wow thanks for the fast replies guys.
I'm gonna go look for the code and I'll post it later.

This is probably going to irritate some members but I confused my resonator for my cat.
I think the technicians took it away without telling us after they replaced the muffler.
I apologize for my mistake, I still have a lot to learn about the Jeep and I'll do my best not to make a similar mistake again.

It's the sensor in the front of the Jeep that's having problems.
And the sensor that we bought is what I believe a universal sensor.
My dad bought it so I'm not so sure.