Aftermarket exhaust fitment issues

mmmkam

mmmkam

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Joined
Apr 25, 2019
Messages
61
Location
VA
I am finishing up a bit of a refresh on my TJ (2003 Rubicon 4.0) and I am 0 for 2 on new exhausts fitting properly so looking for suggestions.

I tried the Magnaflow setup with the mini cats that have a bolt together flange with the magnaflow main cat pipes, but the main cat in that setup is oriented incorrectly and has the exhaust hanger on the bottom vs the OEM with it on top of the cat. Additionally the mandrel bends in the mini cat pipe seem to come further forward or the oil pan and bend out at a wider angle going rearward likely interfering with the suspension. The part numbers on this were:
- Magnaflow 23297 HM Grade Direct-Fit Catalytic Converter
- Magnaflow 50209 HM Grade Direct-Fit Catalytic Converter
The odd thing in researching this after the fact is that the place I ordered them from showed this fitting 00-04, Magnaflow shows it fitting 01-03, but checking Quadrtec they show 00-02.

Next I tried the Flowmaster 2049170 direct fit 2 piece slip joint kit. This one is to wide up front so it either hits the drive shaft. I found a post were @mrblaine talked about losing the flange bolts, jacking up the passenger side to swing it closer to the oil pan, and retighten, but this unit is wide enough that it interferes with the driveshaft , passenger side upper control arm, or both when the suspension articulates. There is no middle ground position that works I will note this unit is listed for 04-06, but I saw several reviews of it being used on earlier model years as well.

I do have a zone combo lift and a small TC drop as well.

Any thoughts or know of a 3 cat setup that will definitively bolt up to an 03 rubicon without clearance issues?
 
Stop buying mail-order (showing my age lol) and just go to your local independent muffler shop. Which doesn't mean Midas, Meineke, etc. since their prices are always much higher.

Just ask them to install a system that has a certain kind of sound, they'll take care of the fit and installation. It will certainly cost no more and likely less than buying those overpriced cat-back systems. Plus you'll have a local warranty and they'll make sure it fits before you drive off. Not to mention they can install nearly any brand you want though I'd go with what they recommend.
 
That sucks, since neither of those are cheap. For cat convertors on the newer 4.0L engines with the dual manifold cat setup I've only had good luck with the Walker setups. They fit like a glove, all the others needed some "tweaking" in order to fit.

As far as the rest of the exhaust (from the cat-back) I agree with Jerry that it's better to just go to a shop and have them build you something, especially on a modified vehicle with suspension changes, TC drop, etc. As far as the manifold cat convertors go it's a bit tougher, since at least in my state many shops won't even touch cat converters unless you are replacing them with a kit that they order for you. In most cases that is big $$$.
 
Thanks for the suggestion I will take a look at walker. The cat back was replaced by the previous owner so I am good there, its just the cats I need swapped out as one of the mini cats was completely gutted after 248k miles.
 
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