Just get a flow master and be done with it, it will sound nice! A guy around town has the dual setup on like a 99 xj with straight pipes, it sounds like its out of tune with y piped duals. And when its at idle n the cold it only smokes from the pass. side, when he hits the gas it comes from both. I saw him at a gas station once and I was asking him what type of muffler he was running and he sad none, he also said it added like 30 hp(ya right). I was thinking man this guy is a tool.

 

If you're not sure, consult a police agency, whether it is local, county or state. Also, you can look up your state's motor vehicle code usually on the internet. Michigan's Motor Vehicle Code is Michigan Legislature Chapter 257 Public Act 300.

Here is a link to the Texas Motor Vehicle Code...you can search if you'd like.

http://law.justia.com/texas/codes/tn.html

 

You can do dual exhaust on an XJ I have never done it, But I have seen it a few times. Although dual exhaust on a 4.0 XJ might not give much of a performance upgrade, It does look nice. And I personaly think it shows that little extra when it comes to customizing your jeep.

Now you can offroad with dual exhaust, But remember if you happen to hit an obsticle with it, well lets just say a single pipe is cheaper to replace.

Also you can run dual exhaust several ways, a y pipe, or a dual outlet muffler off your current a-pipe. Or the newer style XJ exhaust manifolds ran two ports, so you could run true dual exhaust, with 3 cylenders flowing to each tube. But this option would probably mess with your O2 sensor readings. I am shure there is a way to make it work, But might take some trial and error.

 

all you guys saying its pointless ever seen a bmw engine? bmws are historically straight 6 engines also. in the 80s they added a model called a 325i which is a 2.5l I6. every 325i came from the factory with dual exhaust. not a splitter in line under the car, dual from the exhaust manifold with the two pipes run about an inch apart all the way through the cat, the other little piece under there, and then dual out the muffler. and that little 2.5l makes the same power as the 4.0 in our jeeps, 175hp and almost hte same torque.

 

also, texas law says you can exit the side as long as your tip is behind hte farthest rear opening exit for hte cabin.

so, as long as your side exit is past your door (or pop out window if you have one of those) then you are legal by texas codes. you cannot run side pipes though, unless it came from the factory like that (i wanted them on my 65 mustang when i was in high school and couldn't because no one would pass it on the safety inspection)

 

summit racing sells several headers that could be very easly used for duel exhaust... Id get one of them.....

 

I've seen a BMW engine....I've always wanted an AWD 3-series.

 

you want a 325ix. they are great cars and only slightly slower then the normal 325i and 325is. all the ix owners i know love them in the snow. i almost bought one about 5 years ago but the wife didn't want to drive to houston to pick it up so i passed. funny, we ended up driving to houston for a 735i a week later set up identical to the 325i only no all wheel drive.

i would like a 325ix though, i've had all the other models of e30 except that one and hte e30 m3.

 

i've got a flowmaster super 40 already on it

i will probably just side exit the exhaust under the back door with a 3 1/2 inch tip

well.....that might not be a good idea for off-roading.....would probably tear it up...

 

3.5" tip under the back door? like the passenger/driver back door? i hope you have a buddy who can give you your safety sticker then. it will not pass safety inspection legally if your tip is in front of the rear part of the door.

i'm telling you from experience man. i live in corpus and used to live up in livingston and in san antonio. that part of the safety inspection is the same in all counties, its not like the part where some counties hook you upto a smog machine and some don't. that is an asphyxiation safety concern from the exhaust getting sucked into the cabin and choking you out

 

it would be directly under the car. idk my dad says im going to run it out the back lol

 

it has to exit from under hte chassis also. those dumps people run that are under the rear axle are illegal also, in texas. you will normally only see them on classic cars that don't have to be safety inspected or anything like that. plus, under car dumps are horribly annoying in the cabin as the exhaust pulses just vibrate everything and all the space under the chassis allows hte sound to ricochet and reverberate non-stop. gets old really quickly. i had under car dumps on an autocross car and changed them out after one weekend of racing because of hte unneccessary noise they allow. and i am a huge fan of glasspaks and straight pipes. if my wife was down with it, i would run straight pipes on everything i own. (well, from the cat back)

same reason though, asphyxiation from the exhaust gases being sucked into the cabin. you can run them out the side behind the rear wheel though, if you really want side exits, and pass safety.

 

see i put straight pipe for a day from the cat back and dang! it was loud, i liked it but my parents wouldn't let me keep it. I'm just going to run it all the way out the back, i like to see my pipe. im a fan of flowmaster

 

than that'd be your best bet: run it through one flowmaster (since you already have a 40 on there anyways) and y-pipe it out the back, and throw some chrome tips on for style

really, your only main concern at this point then would be to figure a good spot for a hanger on the driver side and a good way to route it through there without hitting anything.

 

lol, man... guy defiantly don't know squat. to really get any gains from exhaust only modification, you have to start from the header back. you just can't through plain old pipes on and be like "yeah, it makes by butt-dyno rumble." well, unless you are into having rumble-butt when you drive, but, meh, not my thing, lol