Why doesn't my 4.0 sound good
Thread Starter
Junior Member
Joined: Jan 2009
Posts: 92
Likes: 4
From: NW GA
Year: 1997
Model: Cherokee
Engine: 4.0
My recently acquired XJ has Dorman headers, high flow cat and a Magnaflow 11256 with 2.5" pipe. It does not sound deep or throaty like some of the sound clips I have viewed on this forum. What's up with that? How can I make this thing sound half way decent?
(deleted comment about cat)
(deleted comment about cat)
Last edited by toddreg; Jun 4, 2014 at 04:28 PM.
CF Veteran
Joined: Nov 2011
Posts: 7,387
Likes: 10
From: City of Trees, CA
Year: 93 2 door
Model: Cherokee
Engine: 4.0
removal of the cat is illegal in all states and discussion of cat removal is not permitted on forums
that being said, if it's not chopped right after the muffler I would start there. chop after muffler, weld on turndown tip
if it already is chopped, that's probably as good as it's going to get. please stand by and wait for some of the actual exhaust pros on this forum to step in and help ya
that being said, if it's not chopped right after the muffler I would start there. chop after muffler, weld on turndown tip
if it already is chopped, that's probably as good as it's going to get. please stand by and wait for some of the actual exhaust pros on this forum to step in and help ya
Beach Bum
Joined: Jul 2011
Posts: 6,123
Likes: 22
From: Cape Hatteras, North Carolina
Year: 2000 WJ
Model: Grand Cherokee
Engine: 4.0
^That is a question that cannot be mentioned or discussed here because it goes against federal law. Editing it out would be a good idea, otherwise a moderator may do it for you (not good).
I think the muffler itself makes the most difference in sound, if you would like a rumble then try a "cherry bomb' type. They are cheap.
I think the muffler itself makes the most difference in sound, if you would like a rumble then try a "cherry bomb' type. They are cheap.
is that Dorman header a long tube design...or is it the same length as the stock manifold?
My Pacesetter long tube header with a spun, hi-flow cat and super 44 sounds hella good...and deep, manly even.
My Pacesetter long tube header with a spun, hi-flow cat and super 44 sounds hella good...and deep, manly even.
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CF Veteran




Joined: Jul 2012
Posts: 3,132
Likes: 357
From: Andover, VT
Year: 1999
Model: Cherokee (XJ)
Engine: 4.0 L
So you have an intake or any other mods? That 2.5" pipe is probably slowing down your exhaust velocity. It might sound better if you get more air in the front. A CAI or bored throttle body may help with the deepness of it.
Thread Starter
Junior Member
Joined: Jan 2009
Posts: 92
Likes: 4
From: NW GA
Year: 1997
Model: Cherokee
Engine: 4.0
CF Veteran




Joined: Jul 2012
Posts: 3,132
Likes: 357
From: Andover, VT
Year: 1999
Model: Cherokee (XJ)
Engine: 4.0 L
It could just be you aren't really a fan of the sound of your muffler. I've always preferred the sound of a flow master over a magnaflow. IMO the magnaflow almost sounds ricey, although I've never heard one with headers and a high flow cat.
I have all stock parts on except for the thrush muffler I threw on to make it a lil louder there bout 3 inches of pipe between the cat and muffler and nothing after the muffler and it sounds good to me
CF Veteran
Joined: Nov 2011
Posts: 3,603
Likes: 3
From: SLC, Utah
Year: 1999
Model: Cherokee
Engine: 4.0L
Goto the exhaust sound clip sticky thread mine is the first video
CF Veteran




Joined: Jul 2012
Posts: 3,132
Likes: 357
From: Andover, VT
Year: 1999
Model: Cherokee (XJ)
Engine: 4.0 L
Yeah that's sounds like a magnaflow if I've ever heard one. Magnaflow has great products, but the design of them makes them sound the way they do. If you want the "deepness" then I'd try another brand muffler like a flowmaster 40. I'm sure there's a ton of other options but I don't really have experience with anything other than flowmasters and cherrybombs.




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