Okay I bought a 00 4.0 ohv 2wd no egr and I'm going to be swapping the engine only it into my 99 4.0 ohv 4x4 no egr. Will I have need to change computer? Will I have to deal with PATS or anything like that. Exactly same motors just wondering if one year difference cause any electricial issues. Thanks!

 

No computer change needed.
May need to swap CPS(cam position sensor) from '99 to '00 unless both are 2-wire.
They changed the 3-wire CPS to a 2-wire in the late '90's.

Change rear main seal on '00 before installing.
Check all the core plugs(freeze plugs) on the '00 while it is out, replace any that have any signs of rust.

If '99 is an automatic and this is your first time, you can ruin the trans if you don't have torque converter in the correct position when you bolt trans to block.

 

Ordered new cam sensor so don't have change in the future. Planned on changing those seals. Both automatics. I'm have a shop pull my motor and install the 00 so I don't destroy anything going in and avoid from doing exactly that. Thanks