Exhaust Question

I have been searching here, CF, and JF for the past four days, and I can't find any information! I am sure someone here will just post a link to exactly what I am looking for and I will feel like a dumb ass.

What is the difference between the pre-96 and 97+ cat backs (Dynomax 17463 and 17340) sans the chrome tip on the latter. I would prefer the early model as I hate chrome.

Has anybody tried to mount an early cat back onto a newer body XJ? If so, what modification, if any, is needed?

id be willing to bet its a difference in the hangar styles... ive seen a few different variations.

I believe later model XJ cat have a flange on the output. Technically, you could either cut it off or weld the flange to the catback system if you get one without.
performance-curve.com, has a catback minus hangars for 100$

Johnnie Walker said:

I believe later model XJ cat have a flange on the output. Technically, you could either cut it off or weld the flange to the catback system if you get one without.
performance-curve.com, has a catback minus hangars for 100$

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I know the 00-01 is supposed to have the two bolt flange on the cat, but my 99 is a slip fitting... currently held together by half a clamp.

PN 17463 for '87-92


PN 17340 for '93-01


The new style doesn't show the added flange piece that is included in the kit, but is unnecessary for my application anyway.

Tail-pipe sections are 2.5" for early, 2.25" for late. Was there any change in the routing, or should I say, crap in the way of routing, between the pre 92 and post 93 XJ?

Muffler part numbers are different, but the early is 2.5" and the late is 2.25" Mufflers only differ in the thickness to accommodate the larger in/out on the late model (in/out locations, width and length are identical)

Clamps included with the kit are for for their respected sizes, but the early model also includes one 2.25" clamp. What is the size of the pre-92 cat-outlet?

Both come with exhaust hanger clamps for the tail section, again early is 2.5" and late 2.25"

Any thoughts?

edit: in my first post I had the year split wrong for the different parts. Should read ~92 and 93~

Thoughts?
Go with the 2.5" and do whatever very minor fab is required to hang it. More flow = more sexy.

On my 89, cat outlet is 2.25, so you should be able to use the early one. Not too bad for 30$ after MIR. But, there are better muffler's out there. I prefer turndowns, myself.

My cat outlet on my 91, 96 and 98 are all slip fit and held together with 0 to 1 U-bolt clamps depending on rust situation. The cat inlet on the 96 and 98 is either U-bolt or welded, I forget, and the 91 has the 4 bolt flange inlet. I am not sure but I think it's a hangar issue also.

This is the flange Corprin mentions- Dynomax says it's for late 00/01 models only.

Ya I have that adapter just sittin around from my catback. The tip is polished steel, not chrome.

Well, I cheped out and bought the early model exhaust. I am going to test fit as soon as it gets here, and see exactly what will be required to fit the early exhaust to a late model XJ.

If it works, $115 shipped - $75 MIR = $40

I just got mine yesterday, the cheap one. Got it installed today, didn't run into any problems on my 98.

98stocker said:

I just got mine yesterday, the cheap one. Got it installed today, didn't run into any problems on my 98.

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I got the cheap "early" one today as well. Less than 48hr from order being placed, and only cost me $11 for shipping, man I LOVE Summit!

So, I decided to do the install rather than work on a paper I have due soon. Install went fairly cleanly, I put the XJ on ramps in opposing corners (left rear, right front) to get max flex out of my stock suspension.







mad driveway flexin' y0!

Removal was simple, and for the first time EVER I didn't have much hassle removing a rusty exhaust clamp.



With the axle crossed up I could easily fanagle the entire exhaust out of the Jeep, no need for the saws-all. I laid out the new tailpipe next to the old one to check for routing issues, they both follow the same exact path over the axle, so I went ahead with the swap.







Didn't get many pics of the install process as it was moving way to quick. Once the Jeep was on the ramps, it only took 32min from start to finish to swap out the system. Sound is a little different, sounds smooth and VERY quiet. Because it's a Walker turbo, I know it will break in to a bit louder and deep tone. I took it out on the road to check for leaks, and it sounded good during WOT from a stop. SOTP power increase is there, but not very much at all.

Clearance above the axle on the 2.5 system is close, but still enough to get by. This is with 235/75-15 and 100% stock suspension with tired rear springs. I will be getting a bit more room when I do the lift in the months to come. I do need to adjust the tail-pipe a bit, and figure out how to modify the rear hanger to elevate the exit an inch or two.











Once I score a welder, I will remove all the clamps and weld her in place.

All in all, not bad for a $40 investment! Only the best for my $2000 hoopty!