While changing my diff fluid I decided to get rid of the stock junker muffler. I Plan on getting an MBRP cat back down the road but this was a $21.49 investment with a surprisingly good outcome.

Parts List:
x1 2.5" exhaust clamp -$2.50
x1 2.5" 45 degree pipe -$5.99
x1 2.5" x 48" long straight pipe with single side coupling-$7.50
x1 JB Weld classic (good to 600deg F)-$5.50

Tools Needed:
-15mm spark plug socket
-(any size ratchet driver)
-Grinder
-Hacksaw/metal jig/cut-off grinder wheel
-A strong table mounted vise is handy

Steps:
1) Use 15mm socket to loosen stock muffler clamp, give it a whack or two to shake off the mud/accumulated crap
2) Use a combination of screwdrivers, grease if you have it, and swearing to pry off muffler from rubber hangers - remove muffler and set aside. DO NOT be tempted to salvage the clamp from the stock muffler, it is welded in place, I drilled the spot weld and it still did not come off- just buy the new 2.50 clamp...much easier.
3) mock up exhaust pieces together and position the elbow on exhaust outlet above rear axle. Decide how you want your outlet pipe to be positioned, I chose a left-swept out. Mark your cut-off with a sharpie, the pipe will extend past the bumper, it's unsightly and puts unnecessary strain on the only hanger position in front of the axle, take the time to hack off the extra length.
4) Grind/polish the exit of the elbow for a clean JB weld surface, it will also make the straight pipe coupling slide on a little easier.
5) Apply JB Weld liberally to the elbow exit, hold the elbow in a table vise (or between your feet on the ground) and hammer the straight pipe coupling over the elbow until it has fit completely. Inspect the JB weld and make sure the pipes are completely sealed together. Allow JB weld to set-up for at least 25min before continuing to work.
6) Mock exhaust clamp onto elbow coupling, most clamps will use the same 15mm nut, fit elbow on to stock exhaust outlet, position how you would like, and clamp. Some may swear by muffler/gasket sealant but I don't have even the slightest fume/liquid leak on the pipe, if you feel the need go for it.

If you want a straight pipe out you will need to bend the elbow ~5-15deg depending on what rear bumper system you have in place, best way to do it is with a mandrel but a vise and pry bar will also work.

Sorry about the lack of pics, I only have finished photo.


I'll spray coat it black sometime next week after it's been burned in and I'm sure the JB has set. It sounds a little gurgly but not too loud or obnoxious. Without the muffler there's a small loss in back-pressure, no noticeable difference in performance but mufflers rarely have any on naturally aspirated gas cars. Sounds nice, cheap, and easy.

 

Good write-up! Probably not legal in all 50 states, but who cares about emissions compliance anyway.

 

Mufflers don't really have any effect on emissions unless they contain a catalytic converter, the JK has dual cats up front about 1ft past each header down-pipe, before the 2 to 1. I passed DEQ (in OR) with no questions asked or even an odd look from the diesely sound.

High-temp rustoleum is going on tonight, i'll post up steps and results after

 

hehehe nice writeup .. i left my exhaust with no muffler for poop and giggles after putting in my banks headers ... sounded grizzly but the lack of power of this engine could never make me justify the sound.

 

Not a good idea on several levels. Just my opinion.

 

care to expand on those levels?

 

Here's one, it came with a muffler and should have one as intended from the factory either stock or after market.

 

It came with a muffler because in states like CA where there are strict requirements for sound and emissions NOT having a muffler can make selling cars there a sticky situation...There is no written law that I am aware of in any state regarding the use specifically of a muffler, every state requires a catalytic converter. The other reason it came with a muffler is because 90% of the people who are buying jeeps off of a car lot do not want their jeep to sound like a 6.1L Diesel king cab...I like the sound so I took it upon myself to change it in the most economical way possible without welding or having to buy a new higher-flow muffler that sounds almost identical to not having a muffler, and pops the back pressure back up to stock.

Anyways, now to how the spray came out.

1) I took the pieces back off after being burned in for ~50hwy miles and some deliberate full throttle take-offs. Cleaned all the pieces with brake cleaner and gave them a thorough scrub down.


2) I picked up some rustoleum matte black high-temp rattle can, rated @1200deg F. VHT high temp primer and matte black were my first options but the rustoleum was cheaper and more available. I can always re-spray later if needed.


3) I sprayed about 3 coats on each side of all the hardware (except the fastening nuts, they're stainless) The stated "to touch" dry time was 25min but I found that it slid off with some pressure and left my fingerprints all over it, the last coats I waited 45-50min each side.


4) When I felt there was ~1/4 of the can left I sprayed inside the pipe, rotating it around while spraying and alternating ends to give the inside as much of a coating as I could. Over-spray really doesn't matter on the inside, no one is going to see it.


5) After the pieces were completely dry (~2hr) I reassembled and changed the mounting angle to curve around the rear springs. I also relocated the fastening nuts to the inside (middle of the jeep) to keep them away from the rear sway bar and body. This way if the pipe catches on the ground or a steep incline nothing will be scratched.


I tightened the fastening nuts to ~150ftlb. It keeps a nice seal and doesn't warp the pipes.

 

True here in NC, you do not have to have a muffler. But be warned that if your in a area with people that complain, you will find a noise ticket. Same as having your radio to loud.


I took mine off and drove around one day, just to see what people thought. I drove by plenty of cops and sat and talked to one. He didnt seem to mind it, more or less every one was rolling cause it sounded like a barking spider. If you get my drift. It was just a little to loud for me as an every day thing, i was also trying to make it roar. So when i finally made it back to the house, i put it back on.


No laws say you have to have one. You might be looked at funny when trading. The true reason it is on there is to restrict flow out. That why you gain horse power when you open it up. Then you loose it when you take it off. Correct the back flow, then you got sound and power.


I cant see any other reasons you could say there levels.

 

Have to chime in here coming from the performance street scene to Jeep clubs in the past 2 years.

A) There are certain manufacturers that produce vehicles with no mufflers from the factory...good example: Dodge Neon SRT4 (dual exhaust and no mufflers stock)

B) Some state laws require that you cannot modify the OEM configuration outside the basic configuration (if you bought it with a muffler, you have to have one)

C) Many states (I can't confirm the figures) only require that you meet the decibel and emissions requirements and pass smog tests

I am a huge believer that many 3rd party manufacturers take advantage of poorly informed consumers in their offering of "Cat-Back" exhaust systems with "high flow" mufflers for $750+.

I've had several high performance vehicles where eliminated restrictive Catalytic converters with high flow options, and run very inexpensive exhaust setups with just resonators to baffle the harsh exhaust noise....AKA, "cheese graters", "cherry bombs", or otherwise.

In a V-6, you have to run wide-open exhaust to get enough harsh noise to get ticketed...

*The views expressed in this post are solely those of the author and do not reflect common interest of any extremely left winged political associations, retirement communities, California Air Resources Board employees and/or associates, or residents of Mobile, Alabama.*