Obd1 upgrade to obd2

[black_mcguyver]

Hey guys I was wondering I got my 1993 2 door cherokee I was doing a motor swap and was thinking if I got a 1996 4.0 could a I pull the OBD2 system and put in my cherokee the motor is from a zj. What all would i need to pull to make it work.

[4.3LXJ]

You could do it if it was from an XJ, however not with the ZJ system. It uses a different instrument cluster, which you would need and a a different transmission, which is controlled by the ECM

[black_mcguyver]

So I'm good with just pulling the motor and worry about the obd2 system later


Sent from my iPhone using Tapatalk

[4.3LXJ]

Yes. Just change the whole intake out. One problem you will have is drilling and tapping a hole for the second temp sensor. I will be putting one on the tstat housing this weekend

[black_mcguyver]

Im lost what will I have to tap and why?

[4.3LXJ]

The OBDI engines use digital sensors for the ECM and have analogue gauges, so they need a second sensor for the gauges. The OBDII uses only one sensor and the ECM uses the same data to control the engine and signal the gauge in the cluster. So you have two temp sensors now and the engine you will use only has a place for one on the tstat housing. I just got done drilling and tapping one for the second sensor. Also yo will need a tiny hole in the tstat, which is a good thing anyway, to allow a tiny amount of coolant to pass the sensors so the gauge will not jump around

[black_mcguyver]

Ok awesome what as far as wiring harness goes do I need


Sent from my iPhone using Tapatalk

[4.3LXJ]

All the engine and transmission related stuff

[Brasscatz]

Another question for you, Steve. Aren't there more O2 sensors on the OBDII system and would that need to be added in order for the computer to have correct readings and outputs?

[4.3LXJ]

Another question for you, Steve. Aren't there more O2 sensors on the OBDII system and would that need to be added in order for the computer to have correct readings and outputs?

There is on the 00, 01 4.0L. Those years split the front and rear three cylinders into separate systems for emissions purposes, so four total O2 sensors

[bluedragon436]

There is on the 00, 01 4.0L. Those years split the front and rear three cylinders into separate systems for emissions purposes, so four total O2 sensors

Yeah the whole 4 O2 sensors is a massive PITA trust me... my GF's LJ has 4 O2 sensors, and have had to change them all twice now.. darn picky thing