88 XJS 5.3 with USA dual Catalytic Converters exhaust system
So upon removing mid exhaust section, I’ve found that the downpipe cats have chunked out. So I’m thinking of buying some non-cat Euro downpipes, and the center box replacement pipes.
I’d still like to run one catalytic converter on each side (no smog check in my state, but I’d like to run one), so I assume i get a muffler shop to fabricate an intermediate pipe with a cat to fit between downpipe and center pipes?.Or buy some intermediate pipes and cut in a cat? Anyone else do this? I see AJ6 Engineering sells cats that fit into the Euro downpipe, perhaps that’s the way to go?
Greg,
I can’t help with most of that because I live in CA and need to keep the exhaust systems in our Jaguars original, complete, and properly functioning in order to pass the CA Smog Checks every two years.
However, I believe that you will have to keep your two downpipe 02 sensors installed and working properly even if you modify your exhaust system otherwise.
Greg,
I don’t know where you are getting that info about CA, but removing two of the catalytic converters from a four catalytic converter XJ-S exhaust system would not be legal. All four catalytic converters would be required to pass the visual inspection and they would have to be OEM Jaguar catalytic converters or California Air Resources Board (CARB) approved aftermarket ones not ones that a muffler shop put together for you.
Greg,
Yep, the rules are a lot stricter. Several years ago I watched a guy with a Mazda Miata have big problems during his CA Smog Check due to a new aftermarket catalytic converter that he recently had installed. The car passed the gas analysis part of the test but failed the visual inspection because the aftermarket catalytic converter that he had installed was not approved for use in CA by the California Air Resources Board. If you look on eBay for catalytic converters you will see that some are specifically approved for CA use and others will be advertised as “Good in 49 states” or “Not Approved for California”.
I faced this exact conundrum. After discovering that my mid-pipes were shot, and really hating the complexity that comes with the stock exhaust routing thru the rear suspension cage, I ended up re-doing the whole exhaust which cost me about $1K plus the cost of Euro down pipes. My local exhaust shop did all the work. Euro down pipes, O2 bungs welded in, two high flow cats, exit under rear suspension. Passes AZ smog check no problem, FWIW. Goes in and out of car as one unit, no messing around try to get it to clear rear cage, etc. Yeah, that was a lot more than I was planning to do, but it is some of the best money I’ve spent on the car.
Yeah I saw that thread. It’s been 12 years and all I remember is that it took a bit of grease and messing around, and I did it without a press and with everything out of the car. I might’ve used a bench vice or a c clamp. Not impossible.
thanks for the exhaust info…I don’t have smog checks here in WA, so I’m tempted to go pure catless, would be so much easier, I could bolt it all up myself. For now, I’d keep the over axles and rear mufflers, as they are fine.
That would work. You can put on the euro pipes and add the O2 sensors. The ? section in your pic is not quite a straight shot from downpipes to beginning of over-axle section, so you’d need to figure out how to get a shop to put some mild bends in a straight piece of pipe, and flare the ends as needed. If you could get the car to the shop (open headers, anyone?) they could do it pretty quickly. I utilized my AAA membership to flatbed mine to the exhaust shop.
Simply Performance sell intermediate pipes and center box deletes that supposedly bolt in perfectly, I could do it myself. About $400 plus shipping. Probably not that much more than having a shop fabricate it.
Question is, do I get 2 cats to save the environment.
Kirbert
(Author of the Book, former owner of an '83 XJ-S H.E.)
13
You could. Supposedly aftermarket cats are $150 each and work better than the OEM Jaguar items, putting a punctuation point on the intelligence of California lawmakers.
Over a decade go, I did drive my “lump” to the muffler shop. Only down pipes, It wasn’t all that loud so long I as my foot was light on the throttle. But mash a bit and yippee!!!
The shop made up a nice assembly. Connecting the in place down pipes to the rear mufflers and resonators.
Two CA OK cats and an “H” pipe.
so far Ok with the Smog shops. I have my doubts as to whether or not they check for the CARB OK. so long as they are present and look the part. Never saw either of my cars on alift???
