all muffler and exhaust questions go here!!!!!!
#4621
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Location: PA
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Year: 2000
Model: Cherokee
Engine: 4.0L
You see how there's 2 tubes separate from each other before it goes into the collector? Yeah... there's 2 small catalytic converters that go there (not included, obviously). IIRC, those are for California Emissions Jeeps only... so if yours is federal emissions, you don't need the cats. You can still get that header, I suppose, and weld it together instead of putting the cats in, but I'd imagine it would probably be less expensive to just find a Fed emission header
Here's the 2 pre-cats:
Here's the 2 pre-cats:
#4622
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Join Date: Dec 2011
Location: Joliet, IL
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Year: 1998,2001
Model: Cherokee
Engine: 4.0
Following this with a question out of curiosity. under Cali emissions (requiring the pre-cats) if someone wanted to for whatever god-forsaken reason go with a dual exhaust after something like Banks Torque headers so it's split 3 and 3, could you fit 2 single pre-cats instead of the 2->1 on the jeep or is this setup necessary in some way for passing emissions? Understandably you'd be throwing cash away by doing this when requiring the main cats and muffles on now 2 lines instead of 1, but for the simple reason of "why the heck not?" could someone do it?
#4623
No, I don't lick fish.
Following this with a question out of curiosity. under Cali emissions (requiring the pre-cats) if someone wanted to for whatever god-forsaken reason go with a dual exhaust after something like Banks Torque headers so it's split 3 and 3, could you fit 2 single pre-cats instead of the 2->1 on the jeep or is this setup necessary in some way for passing emissions? Understandably you'd be throwing cash away by doing this when requiring the main cats and muffles on now 2 lines instead of 1, but for the simple reason of "why the heck not?" could someone do it?
as long as you just cut the Y portion of the pipe you should be just fine. All 4 of the O2s are North of that part and anything after the O2s shouldn't really affect them. Unless you did something real crazy that caused negative pressure at that point, and even then I'm not sure it would really affect it.
I'll say this much though, running a true dual setup will be challenging being as the transfer case is in the way on the driver's side.
#4625
No, I don't lick fish.
Has a lot of clips of exhaust setups so you can hear how they sound.
#4626
Seasoned Member
Following this with a question out of curiosity. under Cali emissions (requiring the pre-cats) if someone wanted to for whatever god-forsaken reason go with a dual exhaust after something like Banks Torque headers so it's split 3 and 3, could you fit 2 single pre-cats instead of the 2->1 on the jeep or is this setup necessary in some way for passing emissions? Understandably you'd be throwing cash away by doing this when requiring the main cats and muffles on now 2 lines instead of 1, but for the simple reason of "why the heck not?" could someone do it?
#4627
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Join Date: Oct 2016
Location: henry county, mo
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Year: 1998
Model: Cherokee
Engine: 4.0 I6
just bought jeep. Not even tagged yet..Noticed something new today.
What to do? Weld? So-called "muffler tape"? Replace?
Also theres big sections throughout the entire exhaust that are blackish. Like its charred.
#4628
No, I don't lick fish.
Muffler tape is a no-go. Stuff is only for holes in the muffler and only a temporary fix... won't do a darn thing on a joint like that. You can either weld it, or replace it. If you have the money, add a flex joint somewhere inline between the cat and the flange for the manifold. That will relieve stress on the exhaust manifold and keep it from cracking again.
#4629
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Location: VA
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Year: 1997
Model: Cherokee
Engine: 4.0
The PO of my XJ had upgraded the ehaust. I found out the muffler is a flowmaster 40 Delta flow but I can't find anything to identify the cat. Any way to identify it? The cat has some knocking and rattling going on inside of it when I first start it sometimes. Once it warms up it goes away. Any idea what would cause the knocking noise? Think it needs replaced?
#4630
No, I don't lick fish.
The PO of my XJ had upgraded the ehaust. I found out the muffler is a flowmaster 40 Delta flow but I can't find anything to identify the cat. Any way to identify it? The cat has some knocking and rattling going on inside of it when I first start it sometimes. Once it warms up it goes away. Any idea what would cause the knocking noise? Think it needs replaced?
Here's a reputable site that sells cats of all kinds. I would recommend the magnaflow 4300 series. Doesn't take up a lot of space, and it's good for motors up to 4.2 liters.
http://performance-curve.com/catalyticconverters.aspx
#4632
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Location: NC
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Year: 1994
Model: Grand Cherokee
Engine: 4.0
Ok, I am thinking about putting a thrush glass packed (cherry bomb) on my ZJ. I have one on my truck which is 3.9 v6 so should it sound pretty much the same?
Last edited by JSJJ388; 10-17-2016 at 12:46 PM.
#4633
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Year: 1997
Model: Cherokee
Engine: 4.0
I don't know of any way to identify it, but if there is knocking and rattling in the cat, it's because the platinum has broken loose. I would replace it.
Here's a reputable site that sells cats of all kinds. I would recommend the magnaflow 4300 series. Doesn't take up a lot of space, and it's good for motors up to 4.2 liters.
http://performance-curve.com/catalyticconverters.aspx
Here's a reputable site that sells cats of all kinds. I would recommend the magnaflow 4300 series. Doesn't take up a lot of space, and it's good for motors up to 4.2 liters.
http://performance-curve.com/catalyticconverters.aspx
#4634
No, I don't lick fish.
As far as what it will sound... no, it will not sound like your 3.9 liter v6. Straight 6 motors have a completely different exhaust sound versus a v6. Straight pipe a v6 and (in my opinion) it sounds like crap... straight pipe a straight 6 and it has a sound between a tractor and a cummins.
All that being said, head over here for exhaust sound clips for a better idea on what X muffler will sound like.
IIRC, there is no 02 after the cat (I KNOW there isn't one on OBDI motors.. can't remember about OBDII), so it won't effect the O2 reading, but it will potentially cause a clog and wind up damming the heat at the cat and upstream. Best for you to replace it for sure.
#4635
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Year: 1994
Model: Grand Cherokee
Engine: 4.0
[QUOTE=Basslicks;3318261]I'm not sure what you mean by "Not worried about emissions as it is pre 95." Federal emissions standards began on all vehicles manufactured after circa 1972... so your 95 XJ (all XJs for that matter) is still bound by federal emissions.
As far as what it will sound... no, it will not sound like your 3.9 liter v6. Straight 6 motors have a completely different exhaust sound versus a v6. Straight pipe a v6 and (in my opinion) it sounds like crap... straight pipe a straight 6 and it has a sound between a tractor and a cummins.
All that being said, head over here for exhaust sound clips for a better idea on what X muffler will sound like.
We do not have emissions inspections on pre 95 vehicles in NC, only a simple safety inspection.
Thanks, ill check those out!
As far as what it will sound... no, it will not sound like your 3.9 liter v6. Straight 6 motors have a completely different exhaust sound versus a v6. Straight pipe a v6 and (in my opinion) it sounds like crap... straight pipe a straight 6 and it has a sound between a tractor and a cummins.
All that being said, head over here for exhaust sound clips for a better idea on what X muffler will sound like.
We do not have emissions inspections on pre 95 vehicles in NC, only a simple safety inspection.
Thanks, ill check those out!