straight piping
Hotshot
Joined: Jan 2011
Posts: 18,849
Likes: 179
From: Puget Sound
Cat cutting might help... but the muffler has no added restriction. All you're going to do by removing the muffler is just make the truck louder... and I hated the sound of mine when I tried it.
Without looking at the performance of your truck with regular gauges or a scan gauge - like AutoEnginuity, Torque Pro, or Dash Command... you're coin-tossing with a keyboard and a cutting wheel.
Without looking at the performance of your truck with regular gauges or a scan gauge - like AutoEnginuity, Torque Pro, or Dash Command... you're coin-tossing with a keyboard and a cutting wheel.
Super Moderator
Joined: May 2004
Posts: 29,380
Likes: 118
From: Central Coast of CA
California prepped f250's and F350's don't have glow plug relay's, they have glow plug control modules, but that doesn't mean they also have catalytic converters.
It used to be hypothesized that the rhyme and reason was the L99 and up 7.3 PSD's with automatic transmissions were catless, but the manual transmission trucks came with cats. However that was disproved a couple years ago.
Then recently (the past year?) someone posted information that gave proper rhyme to the reason Ford put cats on some (very few) L99 and up trucks, but not others (vast majority).
I just wish I had remembered to save the info he posted so I could post it here now.
Damn CRS syndrome......sigh.
Stewart
PS - The E99 trucks were different. I believe they all had cats.
Last edited by Stewart_H; Jun 11, 2014 at 03:17 PM.
Senior User
Joined: Jun 2010
Posts: 362
Likes: 1
From: middlesex county, nj
cut that garbage off, it's stainless steel so be prepared, and also be prepared to replace it because the "cool" straight pipe sound gets old really quick. Also. ...cut the original muffler in half and see if you agree with the post about it not being restrictive
Laughing Gas
Joined: Nov 2010
Posts: 915
Likes: 1
From: oriental NC.
ford sells a cat delete pipe that fits in between where the cat goes . I had replaced mine but have since gone with a whole new exhaust with no cat a mbrp 4in it is much better. I don't know where my pipe is I should have kept it I will look for it. I know I kept the cat just in case but we don't even have emissions in my county on anything!!
Trending Topics
Go Bills !
Joined: Jan 2008
Posts: 2,778
Likes: 65
From: Buffalo, NY
Agreed, In addition be prepared for the weight of the stock mufflers. Them things are heavy and can break a finger. Did two mufflers. Cut the things apart (no cats here though)
Ended up putting pass through silencers on both trucks ( 3 1/2" ) after we got sick of the noise. The silencers brought the noise back down. With the silencers it is normal noise at normal driving. Under heavy load it is slightly louder than stock.
Got the pass thru silencers from summit racing. http://www.summitracing.com/parts/wlk-24216
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Top 10 Ford Trucks Coming to Mecum Indy 2026
Brett Foote
5 Best / 5 Worst Ford Truck Wheels of All Time
Joe Kucinski
i ain't rite
Joined: Mar 2005
Posts: 65,455
Likes: 5,526
From: Marlboro Mental Hospital.
For 7.3's, it's not being California prepped that determines if it has a catalytic converter or not.
California prepped f250's and F350's don't have glow plug relay's, they have glow plug control modules, but that doesn't mean they also have catalytic converters.
It used to be hypothesized that the rhyme and reason was the L99 and up 7.3 PSD's with automatic transmissions were catless, but the manual transmission trucks came with cats. However that was disproved a couple years ago.
Then recently (the past year?) someone posted information that gave proper rhyme to the reason Ford put cats on some (very few) L99 and up trucks, but not others (vast majority).
I just wish I had remembered to save the info he posted so I could post it here now.
Damn CRS syndrome......sigh.
Stewart
PS - The E99 trucks were different. I believe they all had cats.
California prepped f250's and F350's don't have glow plug relay's, they have glow plug control modules, but that doesn't mean they also have catalytic converters.
It used to be hypothesized that the rhyme and reason was the L99 and up 7.3 PSD's with automatic transmissions were catless, but the manual transmission trucks came with cats. However that was disproved a couple years ago.
Then recently (the past year?) someone posted information that gave proper rhyme to the reason Ford put cats on some (very few) L99 and up trucks, but not others (vast majority).
I just wish I had remembered to save the info he posted so I could post it here now.
Damn CRS syndrome......sigh.
Stewart
PS - The E99 trucks were different. I believe they all had cats.
here on the east coast we don't see any of those silly pollution controls on our pre 04 diesels.
although i did once see a cali IDI, and a cali early 90's F3-Superduty-460 with cats come through the body shop to be straightened after fender benders. .
Super Moderator
Joined: May 2004
Posts: 29,380
Likes: 118
From: Central Coast of CA
My old 2002 F250 with the 7.3L PSD (now my daughters truck) is a California prepped truck and it came from the factory without a cat.
Just as aside, all 7.3L powered Excursions are the same as the California prepped trucks with 7.3's. None of the 7.3L PSD Excursions came with catalytic converters.
The gas Excursions and the 6.0L powered Excursions did, but not the 7.3's.
Stewart
Just as aside, all 7.3L powered Excursions are the same as the California prepped trucks with 7.3's. None of the 7.3L PSD Excursions came with catalytic converters.
The gas Excursions and the 6.0L powered Excursions did, but not the 7.3's.
Stewart
Hotshot
Joined: Dec 2005
Posts: 10,247
Likes: 7,666
From: Chino Valley, Arizona
my '97 picked up about 2 mpg with 4" strait pipe exiting in front of the tire. I also put the 6637 filter in at the same time.
it is loud and when towing it is really loud. I wear ear plugs when towing it is so loud.
my '99 I have no idea on mileage or performance as I put 4" strait pipe on it before I ever drove it but it is loud, not as loud as the '97 as the '99 is long bed with a service body so I don't hear it as much.
had I known how loud it would be I would have out a full flow resonator in the '97.
the load in my signature is 10 hours of wearing ear plugs to get home!
it is loud and when towing it is really loud. I wear ear plugs when towing it is so loud.
my '99 I have no idea on mileage or performance as I put 4" strait pipe on it before I ever drove it but it is loud, not as loud as the '97 as the '99 is long bed with a service body so I don't hear it as much.
had I known how loud it would be I would have out a full flow resonator in the '97.
the load in my signature is 10 hours of wearing ear plugs to get home!
Laughing Gas
Joined: Feb 2004
Posts: 822
Likes: 9
From: Leander Texas
I cut the guts out of a muffler and put it on my fathers truck, actually has a nice sound to it and is still quiet in the cab. I have a straight pipe with a homemade thin wall 8"x24" echo chamber with a turn down before the axle that sounds mean when you lay into it, gotten many compliments. It'll make your ears bleed yanking a load for extended periods though. It sounds like a common rail killer, though it's not.
Laughing Gas
Joined: Nov 2010
Posts: 915
Likes: 1
From: oriental NC.
quoted from TJC TRANSPORT
[here on the east coast we don't see any of those silly pollution controls on our pre 04 diesels.
my truck is a early bird 6/98 ordered from va. built in Kentucky 6-sp manual it had a cat factory I know because I ordered the truck new and I still have it ! the truck not the cat. only the one glow plug relay nothing else
[here on the east coast we don't see any of those silly pollution controls on our pre 04 diesels.
my truck is a early bird 6/98 ordered from va. built in Kentucky 6-sp manual it had a cat factory I know because I ordered the truck new and I still have it ! the truck not the cat. only the one glow plug relay nothing else
Super Moderator
Joined: May 2004
Posts: 29,380
Likes: 118
From: Central Coast of CA
my truck is a early bird 6/98 ordered from va. built in Kentucky 6-sp manual it had a cat factory I know because I ordered the truck new and I still have it ! the truck not the cat. only the one glow plug relay nothing else
2003 6.0L PSD's were all sold with pollution control devices too.
The east coast is not exempt from federal government requirements and standards.
Stewart