EMAXX620

Got a small problem here. I just dropped a HP d30 into my 2000xj, and since the driveshaft sits up higher now, it crushed my exhaust manifold when i did some very minor offroading. My buddy said he had the same problem a few years back and said he "THINKS" he just bolted up a older style 1 piece manifold (versus my 2 piece)

Is this possible? I didn't think they were interchangeable.

Any help would be much appreciated. Have a mudbog i'm supposed to go to in two weekends, and would like to run in it.

882door

Getting the same thing with mine.

My solution is going to be coil spacers for a little more lift.

Already has a 3.5 (4.5 actual) lift.

EMAXX620

I'm at 5.5" now (probably a bit higher) and am having this problem. Just hope i can solve it before the mud bog haha.

Jeepasaurus9

You can do it... put you'll have to have some bungs put in for the oxygen sensors. It will bolt right up to the head. Aftermarket heads are made to fit the largest exhaust ports and '00 and '01 Cherokee's have the smallest exhaust ports because of emissions laws. Heats up faster. Larger intake... smaller exhaust.

2000 and 2001 cherokees have two oxygen sensors (one on each flange) on the "Y" down pipe. Here is some info on the o2 sensors and bungs on the exhaust... bungs.
https://www.cherokeeforum.com/f67/o2...-bypass-76541/

882door

I don't know if a manifold change will work. Never seen the two piece.

salad

It won't without those O2 sensors and mini-cats. Removal of which is not permitted on this forum btw.

The proper fix is to lift it and bumpstop it. Proper bump stops are very important. You can use hockey pucks up front lol

Dan91

You guys sure that it's not the factory clearance dent in the down pipe? They crushed them right at the beginning of the down pipe for front driveshaft clearance intentionally.

882door

Pretty sure. Giant cut marks, gashes, dents, all fresh and with matching rub, scratch, and dent marks on the u-joint.

Mine's been cut through in several spots, and has bent the pipe over against the oil pan and bent the bolts on the donut flange.


Might not be factory....lol

salad

That's a common conception, in reality the earlier models work better without that crush. The Walker downpipe and some other aftermarket units don't have it. It's actually to create a higher EGT to speed catalytic converter heating.

Dan91

Oh yeah, I know it isn't really a nescessary or helpful thing, I was just mentioning that it was put there by the factory.

EMAXX620

I think they started that 2 mini cats and extra o2 sensors in 01 or late 00. Mine never had them on it, but the manifolds i got from a late 01/early o2 had the bungs for the extra o2 sensors.

And yeah, I'm positive it isn't the factory "dent" on the manifold, in fact, i just replaced it with a new one because my old one rusted through, and the dent wasn't there on the new one, and you can see gouge and scratch marks from the drive shaft, and i heard it hit

So the old style manifold will for sure mount right up?

evan00xj

Ive battled this problem for a long time. And im not talking scraping at full flex. Im talking driving around town with no front drive shaft and still scraping over small bumps in the road. (Thats lifted 4") PO had swapped a hp 30. Ended up throwing in a LP to get clearance. Was my only option at the time. I had just reinstalled my banks header and had just replaced the mini cats. My 2000 has 4 02 sensors total. Gotta pass emissions and keep it legal....is what it is.

evan00xj

Just sharing my personal experience with the hassle and PITA associated with the 2000-01 exhaust system. As you can see the old nasty clogged pre cats were hitting and you can see how the brand new ones suffered the same issue.

caronaxtr

I'm rebuilding a HP D30 right now myself & am really concerned with this issue. Is there a fix to it? I'm at 5.5-6" of lift. I'd hate to have to get some custom exhaust made.

evan00xj

Ive spent hours researching this problem and really haven't seen many people with issues as bad as mine. Like i said its not a fix as simple as using bumpstops.