1999 Drivetrain into 2000 body, what's different?

Destroyer · Sep 24, 2014

Looking to swap my low mileage 1999 drivetrain (4.0, AW4, 231) into a 2000 body with the same drivetrain. What all has to change to get everything to play nice? I know the coil pack vs. distributor is different so figuring the engine harness and computer has to move over, but what else changes? Trans control the same, any evap/emissions junk?

lazyxj · Sep 24, 2014

Make it easy on yourself and keep all the 2000's electrical and electronics.
Swap the 99's distributor for the 2000's cam sensor housing and use the 2000's coil pack.
Search here for DIY coil brackets, the ones used when replacing a 0331 head with an earlier head.
I don't know when the AW4 received the input and output shaft speed sensors, something to research.

cal · Sep 24, 2014

98 the aw4 changed, so trans is good.

Destroyer · Sep 26, 2014

So just that easy then, re-use the 2000 electronics and harness by swapping the coil packs onto my head, and everything else is the same or otherwise usable? How about the exhaust, can I use my current header/downpipe (fully custom, built to fit with my flat belly setup) in the 2000 or do the newer exhaust use multiple upstream O2's?

Thanks for the advice!

lazyxj · Sep 26, 2014

Destroyer said:
How about the exhaust, can I use my current header/downpipe (fully custom, built to fit with my flat belly setup) in the 2000 or do the newer exhaust use multiple upstream O2's?QUOTE]

AFAIK, all 2000 XJs had 0331 heads(small exhaust port) and some had the Calif-version with the two mini-cats just below the exhaust manifold.
The California version has 4 O2 sensors, two upstream and two down stream, all on the mini-cats and none on the main cat converter.
The exhaust ports on your 99 XJ's headers will not match the 2000's head so use the 2000's headers and mini-cats is equipped. Not using all 4 O2 sensors, if so equipped, will set a CEL code and turn the Check Engine light on.
If the 2000 is a Federal model, this isn't a consideration.

Talyn · Sep 27, 2014

Use the electronics in the vehicle the engine is going into.

lazyxj said:
The exhaust ports on your 99 XJ's headers will not match the 2000's head so use the 2000's headers and mini-cats is equipped. Not using all 4 O2 sensors, if so equipped, will set a CEL code and turn the Check Engine light on.
If the 2000 is a Federal model, this isn't a consideration.

If he has an aftermarket header on the 2000 the runners on the header usually have no problem covering the earlier exhaust ports.

thatxjguy · Sep 27, 2014

If you do the 1999 distributor swap, I believe you're going to need to use the 1999 computer.

1999 Drivetrain into 2000 body, what's different?

Destroyer

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lazyxj

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cal

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Destroyer

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lazyxj

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Talyn

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thatxjguy

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