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95 4.0 in 2000 XJ O2 Sensor Question

Cbates1

NAXJA Forum User
So I bought a 2000 XJ that had a motor swap done with a 95 4.0. I’ve had jeeps on and off all my life and I wanted a new project so I found this for $550 and pulled the trigger. I want it to be able to pass emmission and get it on the road. It has no down pipe or exhaust system just the header for the 95. So obviously I’m getting codes for 02 sensors and im getting four of them 1/1, 1/2, 2/1, 2/2 since the 00-01 has the 2 cats. I’m going to get a down pipe from a scrap yard and have my buddy weld up an exhaust. My question is how can I get away from all four codes? I’ll only have 1 before the cat since it’s a pre 00 header. Pictures for reference on which header it is.
 
It would depend on your state's emission laws. If it's got a 2000 ECU you most likely will have restore it to a 2000 compliant model.
 
It would depend on your state's emission laws. If it's got a 2000 ECU you most likely will have restore it to a 2000 compliant model.
I thought about changing the ECU to a 97-99 but I’m not sure if that would work or not.
 
Are those the only 4 codes you have? If so, you could possibly drill 2 holes and weld in a 2 more bungs. Another issue is you will have to lengthen the wires to the after cat O2 sensors since they are in a way different place on 00-01s.
 
Is it titled as a Federal or California emissions? Where are you trying to get it registered? A early ECU won't be easy with all the changes on a 2000-01.
 
The PCM does not know or care when the engine block was built, so you can install the necessary 2000 parts to make it run correctly.
 
Are those the only 4 codes you have? If so, you could possibly drill 2 holes and weld in a 2 more bungs. Another issue is you will have to lengthen the wires to the after cat O2 sensors since they are in a way different place on 00-01s.
Along with the 4 02 codes it has a P0118 engine temp cooler code which I replaced the sensor already, it has a P1694 that says manufacturer control, also a P0122 throttle/ pedal position sensor Switch A circuit low. A buddy of mine did suggest we just weld on 2 bungs on the 95 exhaust header one the 123 and 456 respective sides and then 2 after the cat we install. Wasn’t sure if that would be sufficient or not.
 
Is it titled as a Federal or California emissions? Where are you trying to get it registered? A early ECU won't be easy with all the changes on a 2000-01.
I’ll have to wait until I get the title back from transferring it. There is a Virginia sticker in the windshield, it was found in PA, then titled in MD and now will be title in PA again where I live.
 
Might check PA laws. There might be an exemption for vehicles 25 years or older. I do have a JBA header for a 2000+. Kind of a pain to install though. Not sure when I'll get back to PA.
 
Might check PA laws. There might be an exemption for vehicles 25 years or older. I do have a JBA header for a 2000+. Kind of a pain to install though. Not sure when I'll get back to PA.
I did actually just snag a stock header with the downpipe and precats with the sensors on marketplace for $75 it’s in great condition. And found a guy on one of these forums who makes an adapter plate to go from the 7120 block to an 0331 header so I’m just gonna go with that I believe
 
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