XJ OG

Hey fellas,

I am in the process of buying the final components for my exhaust. I am replacing everything from the front exhaust pipe, cat, and tailpipe.

Magnaflow cat for my 2001 xj rear cat

Flowmaster Super 44 with Madrel 2.5" inch tailpipe that I bought from performance-cure.com
https://performance-curve.com/84-01-...er-44-muffler/

Adapter pipe
https://performance-curve.com/2-5-od...-adapter-8942/

Mandrel Bent 2.25" front pipe
https://www.autozone.com/emission-co...920/150878_0_0




3 questions:

1).
-I need help finding:
*Gasket and end bolts that will fit the new front pipe at the header
*Gasket and end bolts for both sides of the new cat
*What clamps and how many will I need?

2.)
-The mandrel tailpipe that goes with the super 44 ends up being several inches short and ends under the truck instead of being flush with the rear bumper. There is about 8'' inches of missing pipe from the cat. So i need to buy a 2.5 extension pipe to cut and install in order to fill in the gap.

Would this work?

3.) What kind of hangers and how many should I use?

4.) Is anything else i am missing here?

2DrXJRegulatorFix

The Super 44 has a nice sound to it with the 4.0. The gaskets can be found on rock auto and there are flange connections on summit racing. I'd suggest having someone weld the flanges onto the super 44 and the cat. If you don't you'd need 5 clamps (2 for the cat, 2 for the muffler, 1 for the tailpipe). Bolts you can find at any hardware store.

Old Man Minimalist

Tagging for interest. I'm changing my exhaust on my '99. My manifold was cracked so I purchased a new one. Word of caution: the ATP PN 101212,"improved aftermarket version" does not fit. The number 6 tube interferes with the intake manifold and won't allow the intake to mate to the head. I suppose you could grind off the offending section of the manifold but I'm trying to keep this XJ as close to factory as I can. I ordered PN101330 which is the version with the bellows but Rock Auto sent the "improved" one by mistake and said I could keep it. Unfortunately it is going back and I wait for the replacement. Hopefully that one will fit.

I will say this about the ATP manifold: the welds looked really good and there was no flash to grind off the manifold either inside the ports or outside. It was a good looking manifold.

I'm reusing my front pipe and CAT but need to get a muffler and tailpipe.

OG, in your research did you come across any stainless steel tailpipes? I'd like to replace mine with one like the factory one. The muffler is shot on mine, mostly due to be using a hammer to get it off the CAT, oops.

third coast

Walker Maga-Clamp is worth a look. They are more forgiving on exact length of pipes and It makes install much easier if you are doing it yourself.

My bulld thread may have some info you will find useful on exhaust. Mine is a '91 but there are a lot of similarities. Check if your manifold header to down pipe interface uses a bolt system with a spring, unusual nuts, etc and specific donut like seals (or if it came from the factory that way) I recommend going with the OE approach. It was designed to help with thermal expansion and alignment and minimize stresses on the manifold. Search and you should be able to find an illustrated parts breakdown for your year. I believe I got some OE exhaust hardware and the rear hanger from my Chrysler dealer. Sometimes OE is best.

Jim Malcolm

+1 on the Walker Mega-Clamps

Old Man Minimalist: https://upsw.com/1999-jeep-cherokee-...il-pipe-a19987

awg

I have a Flowmaster 2-1/2" system and it gives noticeably better power, and to most ears a better sound

People notice my vehicle because it has a fairly unique exhaust note

In my opinion it is hands down the best easy power improvement you can get on a an XJ, especially if the OEM exhaust, which is designed to be restrictive to help emissions is up for replacement

bluejeep2001

None of those listed parts look like it will get you from the collector flange after the primary cats to the intake of the rear cat. It needs to go across but also bend 90 deg fwd to mate to the front cats and needs to turn 90 deg rearward to mate with the 2nd cat unless the 90 deg bend is built into the magnaflow cat

straws

Agreed. I'm currently redoing my exhaust from the manifold back and I'm not seeing in his list of parts the downpipe from the manifold that crosses over to the cat.

XJ OG

Are you referring to the front pipe? the website says direct fit.

straws

Do you have pictures of your current exhaust setup? I know the '01 is different with its two pre-cats so there might be a different crossover member.

XJ OG

Sure, Give me a second. I snapped some pics of it last week when I had her on the lift. You will see where the cat broke off from the pipe.

Front pipe starting at the headers



As you can see the cat broke from the front pipe and is bouncing up and down while i drive.


Another angle of the existing rear cat



Not sure but I believe this is a pic of rear portion of the front pipe that goes towards the rear cat.

XJ OG

Hey guys,

I just want to make sure I have all the correct piping and components so everything connects from the front pipe to the tailpipe and everything in between. FRONT PIPE->REAR CAT->MUFFLER->TAIL PIPE
Can someone explain what I have to do and what to buy in order for the front exhaust from the collector flange to the rear cat intake to fully connect?
Are you saying I need an additional 2.25" extension pipe in conjunction with the front pipe I ordered in order for it to connect to the rear cat? Then 2.5" to connect the rear cat to the muffler?
I am trying to see where you're coming from and what I am missing..
Also, the Mandrel tailpipe that came with the Super 44 from Preformance-Curve falls short in length and is not long enough to be flush with the rear bumper. How do I make it so the exhaust reached the rear evenly?

bluejeep2001

walker 53440 appears to be the one you need according to the walker catalog

danej1026

I am glad you are tackling this upgrade. I’m am ready to do the same. How did yours turn out?

2DrXJRegulatorFix

Measure the length of the stock cat from where it bolts to the front pipe to where it bolts to the muffler.

Measure the length of the stock muffler from where it bolts to the cat and clamps to the tail pipe.

Have a shop weld the flanges onto the cat and the front of the muffler so they're the same lengths as the above measurements. Or just have them add the flange to the cat and clamp the other parts.