I've put it off for as long as possible, but inspection's coming up, and my 2000 XJ (85,000 miles) is still throwing p0432 (main catalyst efficiency below threshold, bank 2) which means it won't pass PA emissions. And it's a California compliant vehicle, to make things ever so much more fun.
I've dug a lot of useful info out of the forums, including a replacement finder off this thread (https://www.cherokeeforum.com/f2/cat...verter-117975/) which pointed me toward a Walker 81850 as a compliant replacement. $400 sounds a lot better than the $1700 the dealer quoted me for the OEM part from the factory, so I've just got two questions still to answer:
First, anyone also cursed with California cats have any experience with that particular replacement catalytic? Will the computer shut up about the P0432 code? Everything I've heard/read also says that code is almost definitely the cat, though there's a slim chance it could be a bad O2 sensor as well. But either way, the old O2 sensors are pretty much fused into the old cat, and I'm planning on getting new OEM ones in during this job.
Second, anyone know what the labor's like in changing those cats out? When I was last wriggling around underneath, I had the really nasty feeling that you'd have to pull the whole exhaust manifold off to get the damn thing out, but if it's possible to get at it from the underside that'd be helpful to know. Or at least I could let my mechanic know what he's in for, since I think this job is going to be beyond my little shop.
Thanks

 

Must replacements are weld in from what I remember. I know I ordered my replacement cat from www.californialegalconverters.com for another of my cars a while back and it was a bolt on for that one. The ones for the jeeps look like weld in but they could just be stock photos

Max

 

Well welding's definitely beyond my current capabilities, though when I ran a search through CALegal the part they came up with for the 2000 XJ claims to be bolt on only, and $150 cheaper to boot. Unfortunately it's also out of stock. The Walker model lists 'Connection Type - 2 Bolt Loose Flanges Inlet and 3 Bolt Welded Flange Outlet Connection' so... bolts on the inlets and weld on the outlet? Or bolts on both sides, with the outlet flange already being welded in place? Not quite sure how to read that. Thanks for the pointer though.

 

Have you tried replacing the sensors (original 14 yo ones)? Sometimes they almost fall out, looks can be deceiving.

 

Yeah, tried pulling the sensors. Didn't go well. I was able to get a wrench on one of the downstreams and couldn't budge it in the slightest, with or without heat. And that area is so cramped that without a lift to give you some maneuvering room getting hold of the front downstream seems impossible, to say nothing of the upstream ones that are buried up right under the exhaust manifold. Times I miss my old '96 with one cat in the normal spot; changing the O2 sensor on that took about 10 minutes. Thanks for the reply.

 

Might consider getting your parts and going to an exhaust shop for the install, win/win then as far as price and correct replacement.

 

Did you soak them in penetrating oil first? They might loosen up if you douse them in Kroil or PB Blaster and let them soak. Let 'em soak for a day, then hit them again. Repeat for three days. THEN try to get them out. Also, if they don't want to turn, try tightening them slightly before loosening to break the hold. To me it would be worth the effort to try replacing them before potentially tossing out $400 on cats I didn't need.

The catted downpipe should be a bolt-in replacement. I haven't replaced one myself, but my understanding is that those top bolts are not easy to get to and will likely be just as seized up as your O2 sensors. You will want to soak them before trying to get them out.

Personally, I'm with Fred. Order the parts and just get a muffler shop to put them on. It would be worth the labor cost to avoid that headache.

 

Looks like 00 cats should have flanges on both ends and be bolt in (the "direct fit" ones specifically for an XJ) so you shouldn't need to weld it.


In make sure to have new bolts on hand and something to cut the old ones, they tend to rust to hell and seize up.


Looks like RockAuto has a California compliant cat for $202.79 (Walker Part # 82799): http://www.rockauto.com/catalog/x,ca...,parttype,5808


Note: Flange Gasket (Walker Part #31625) also required:
http://www.rockauto.com/catalog/x,ca...,parttype,5836


The Walker 81850 the OP mentioned is for the pre-cats (also flanged) which bolt directly to the manifold. I don't think these should throw a code on their own (since they only have O2 sensors after the cats not before (maybe someone else can confirm this), though if the OP can't get the O2 sensors out to replace them it may need replaced as well. As extrashaky noted, hit them with lots of penetrating oil and get the engine hot (be careful not to burn yourself), this generally makes them easier to get out.

 

The '00 and '01 California emissions XJs have FOUR O2 sensors. Two are before the precats in the manifold. Two are after the precats in the downpipe. Here's a stolen pic:




The '00 and '01 CA emissions XJs have a third cat in the normal place under the passenger mid/rear of the Jeep, but it does not have any O2 sensors back there.

Also, Chrysler was doing some strange things during '00 and '01, and not all of the trucks came with bolt-together flanges in their exhaust. Some of them are slipped together and welded. If I'm not mistaken, OP has already been under his truck and confirmed that he has a flange at the end of his downpipe, so these bolt-on replacements should work. But when dealing with an '00 or '01, you have to look under there and visually verify which version you have before ordering exhaust parts.

Luckily I ended up with an '00 EPA emissions XJ. It doesn't have the precats and only has two O2 sensors in relatively easy to reach places. I was also lucky enough to get one with bolt-together exhaust. So my upgrades were relatively easy. The EPA version was not offered at all in '01.

 

Shaky's got it; there are 4 total O2 sensors, as shown in the picture. I was able to locate them all easily enough, but getting any torque on any of them except the downstream rear (lower right in the image) was a whole new problem, especially with the jeep still on the ground.

My mechanic seconds replacing just the O2 sensors first before doing the whole pre-cat, so I think I'm going to leave that to him next week when I don't need to drive anywhere for a couple days. I'll post the results back up; be nice if it was just the O2 sensors, but at worst case the Walker parts pointed out here save me a huge amount of money over the OEM price.
Thanks.

 

Yes always give the O2 sensors a shot first. You can't lose out as they are regular maintenance items (albiet less regular than some other components!), and the 2000+ PCM uses all four sensors to set the fuel mix.

So you're in PA with a 50-state Jeep? COuld be worse, at least you don't need official CARB-approved components!

 

They sold them all over. When I was looking for mine new back in 2000, we had a line on one in Alabama that had CA emissions and passed on it. At the time I didn't really know what the differences were, but I'm glad we waited for an EPA truck.

In 2001 there were no 49-state EPA trucks. ALL of them were CA emissions. It was easier for Chrysler to just have the one exhaust system rather than two.

 

Yeah, I realized that after posting. We got a mix of 50- and 49-state models for 2000.

My point is that while we may say one system is "California spec", he doesn't need official CARB-approved equipment unless he's in a CARB jurisdiction. HUGE cost difference!

 

This is true, which is why he can buy the $200 precat downpipes from Rock Auto instead of the $400 ones he's been seeing elsewhere. Before this thread I didn't realize anybody made a cheaper set of precats that weren't CA legal. It makes sense though, since the computer needs the cats there to get the correct readings from the O2 sensors even if you're not in nanny state California.

 

Yep, if the OP needs pre-cats he should be able to use either Walker # 52304 (Pre cats that fit California emissions vehicles but aren't actually CARB approved) for ~$180 vs. Walker #81850 (the actual CARB approved pre-cats) for ~$400.


Note: if the OP ever plans on moving to New York they also require CARB approved components on California-emissions vehicles (according to RockAuto).