Notices
1997 - 2003 F150 1997-2003 F150, 1997-1999 F250LD, 7700 & 2004 F150 Heritage
Sponsored by:
Sponsored by: Auxito

UHH Cats

Thread Tools
 
Search this Thread
 
Old Sep 20, 2008 | 08:58 PM
  #1  
ole_smokey_88's Avatar
ole_smokey_88
Thread Starter
|
Senior User
Joined: Jul 2007
Posts: 174
Likes: 2
From: G-VEGAS TN
UHH Cats

I was just wandering if i removed the two back cats would it mess anything up ??

Thanks
ole_smokey_88
 
Reply
Old Sep 20, 2008 | 08:58 PM
  #2  
ole_smokey_88's Avatar
ole_smokey_88
Thread Starter
|
Senior User
Joined: Jul 2007
Posts: 174
Likes: 2
From: G-VEGAS TN
oh by the way its a 2002 f-150 5.4 ltr motor
 
Reply
Old Sep 20, 2008 | 09:15 PM
  #3  
TheTinian's Avatar
TheTinian
Posting Guru
Joined: Apr 2006
Posts: 1,218
Likes: 0
From: Fl
Not again.....!!! Do a search youll see.
 
Reply
Old Sep 21, 2008 | 07:02 AM
  #4  
xtrford's Avatar
xtrford
Posting Guru
Joined: Jul 2005
Posts: 1,940
Likes: 0
It is a sensitive subject around here along with anything to do with gas mileage. That shouldn't be reason why you can't ask though.....just remember; opinions are like a**holes...we all have one.

"If" you want my opinion, there are no real gains to be made if that is what you are implying, and you will have a bright "check engine light" staring at you while you drive.
 
Reply
Old Sep 21, 2008 | 11:44 AM
  #5  
ole_smokey_88's Avatar
ole_smokey_88
Thread Starter
|
Senior User
Joined: Jul 2007
Posts: 174
Likes: 2
From: G-VEGAS TN
well there is four of them and all im really wantin to do is make my flowmaster bark a lil louder i was just gonna maybe take the back two off but there is no o2 sensors around them or nothing i mean i'll still have my front two those are the ones that really matter aint it ? im new to the whole emissions stuff i got a 88 and a 89 with no cats
 
Reply
Old Sep 21, 2008 | 01:42 PM
  #6  
xtrford's Avatar
xtrford
Posting Guru
Joined: Jul 2005
Posts: 1,940
Likes: 0
Actually it is the opposite. The front are pre-cats or heaters and the rears are the ones that matter. Some around here and other sites gut the fronts and keep the rears claiming better sound, performance and such...I personally don't like to muck with them because they are pretty free-flowing enough.

If you are looking for more sound the cheaper alternative would be to cut the flowmaster out and weld in a piece of straight pipe in its place. I did and it sounds pretty good and loud.
 
Reply
Old Sep 21, 2008 | 09:56 PM
  #7  
ole_smokey_88's Avatar
ole_smokey_88
Thread Starter
|
Senior User
Joined: Jul 2007
Posts: 174
Likes: 2
From: G-VEGAS TN
Cool thanks for the help man i really appreciate it

Ole_smokey_88
 
Reply
Old Sep 22, 2008 | 12:03 AM
  #8  
ATC Crazy's Avatar
ATC Crazy
Hotshot
Community Builder
Loved
Community Favorite
Top Answer: 10
Joined: Jun 2003
Posts: 12,360
Likes: 4,394
From: SW VA
Originally Posted by xtrford
and you will have a bright "check engine light" staring at you while you drive.
I disagree. At least in my case. All 4 of mine are gutted. After 1500+ miles, no CEL. It did come on about 200 miles after I originally gutted them, but AdvanceAuto is on my way to/from work so I had them reset it once.


Originally Posted by xtrford
Actually it is the opposite. The front are pre-cats or heaters and the rears are the ones that matter.
Wrong. All 4 are 'real' cats. No such thing as "pre-cats" on these trucks.



"ole_smokey": If you have the extra time to kill, and nothing to lose...then go ahead. You will lose a small ammount of low-end torque, it will smell like an old hot-rod, and there is a chance the CEL will continue to come on. But you will get A LOT more sound out of it.
If I had to do it all over again, I would have left mine alone purely for the fact that I'm trying to sell it. If I were to keep it for the rest of my life, then I would be fine with it. I had the entire exhaust out of my truck when I was replacing the manifold gaskets...so I said "F-it" and went for it...



If you do plan to gut them, this is where you will need to cut and re-weld the pipe on both sides:









....and here comes Club Wagon....
 
Reply
FTE Stories

Ford Trucks for Ford Truck Enthusiasts

story-0

10 Ways Ford is LOSING to the Competition

 Joe Kucinski
story-1

Top 6 Best Deals Available on New Fords & Lincolns Right Now

 Brett Foote
story-2

This Hennessey Takes the Expedition Tremor's Off-Roading Capability to the Next Level

 Verdad Gallardo
story-3

Top 10 Fords at 2026 Carlisle Ford Nationals

 Joe Kucinski
story-4

3 Best / 3 Worst Parts of Modern Ford Ownership

 Brett Foote
story-5

10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches

 Pouria Savadkouei
story-6

Every 2026 Ford Engine Explained

 Brett Foote
story-7

10 Ugly Ford Trucks That We Still Kinda Love

 Joe Kucinski
story-8

10 Things Every Truck Owner NEEDS (2026 Edition)

 Michael S. Palmer
story-9

Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath

 Verdad Gallardo
Old Sep 22, 2008 | 02:21 AM
  #9  
advocate's Avatar
advocate
Senior User
Joined: Apr 2006
Posts: 331
Likes: 0
Do yourself a favor and don't "get them"....
you're doing nothing for performance. just making it sound like a badly tuned chainsaw. Do the right thing and replace them with 2 or 4 high flow cats or at very least weld in some straight pipes rather then gutting the cats and leaving big expansion chambers to mess up your exhaust velocity.

I went with the idea of welding in 2 high flow cats in place of the 4 when my front 2 cats had become destroyed. I just cut them all out and put 2 new ones in in place of the back 2. Sound is great, no CEL, power and fuel economy are still there.
 
Reply
Old Sep 22, 2008 | 07:07 AM
  #10  
xtrford's Avatar
xtrford
Posting Guru
Joined: Jul 2005
Posts: 1,940
Likes: 0
Originally Posted by ATC Crazy
Wrong. All 4 are 'real' cats. No such thing as "pre-cats" on these trucks.
Really?? I was under the impression the fronts were just there as heaters to burn off fuel from a cold engine start, and the rears were purely for emissions.

Regardless, I don't see any benifets from removing or gutting them if you plan on keeping the truck for some time.

Any luck selling your truck yet ATC?
 
Reply
Old Sep 22, 2008 | 02:06 PM
  #11  
Club Wagon's Avatar
Club Wagon
Posting Guru
Joined: Feb 2007
Posts: 2,351
Likes: 8
You guys were on this like flies on stink, looks like there's little need for me to argue against removing cats yet again. You beat me to it!

xtrford: "there are no real gains to be made if that is what you are implying, and you will have a bright "check engine light" staring at you while you drive"

"Regardless, I don't see any benifets from removing or gutting them if you plan on keeping the truck for some time."


Originally Posted by ATC Crazy
If you have the extra time to kill, and nothing to lose...then go ahead. You will lose a small ammount of low-end torque, it will smell like an old hot-rod, and there is a chance the CEL will continue to come on.

If I had to do it all over again, I would have left mine alone purely for the fact that I'm trying to sell it.

and here comes Club Wagon
I still recall when I used to get attacked for posting the valid reasons not to remove cats. Nice to see converts placing the dubious pursuit of sound into perspective & enthusiastically carrying water for performance, emissions, value & perhaps even the Federal Clean Air law that set penalties for removing cats.
 
Reply
Old Sep 22, 2008 | 02:55 PM
  #12  
whalebird's Avatar
whalebird
Senior User
Joined: Dec 2003
Posts: 212
Likes: 0
From: Spruce Pine, NC
I agree with club wagon, also there are noise issues. I don't know why every harley guy takes the mufflers off their bike and every kid cuts a perfectly good exhaust system off a vehicle for no reason other than to make noise. There should be enforcment of noise regulation. I strongly suggest you leave the cats and mufflers of your truck. Give your community some piece and quiet. OK, I am off my soapbox.
 
Reply
Old Sep 22, 2008 | 03:26 PM
  #13  
TheTinian's Avatar
TheTinian
Posting Guru
Joined: Apr 2006
Posts: 1,218
Likes: 0
From: Fl
Originally Posted by ATC Crazy
I disagree. At least in my case. All 4 of mine are gutted. After 1500+ miles, no CEL. It did come on about 200 miles after I originally gutted them, but AdvanceAuto is on my way to/from work so I had them reset it once.
Mines on and off. It will stay on for a week or two, and then go off, and its been off for a good month now. Dont bother me none though....

Originally Posted by advocate
Do yourself a favor and don't "get them"....
you're doing nothing for performance. just making it sound like a badly tuned chainsaw. Do the right thing and replace them with 2 or 4 high flow cats or at very least weld in some straight pipes rather then gutting the cats and leaving big expansion chambers to mess up your exhaust velocity.

I went with the idea of welding in 2 high flow cats in place of the 4 when my front 2 cats had become destroyed. I just cut them all out and put 2 new ones in in place of the back 2. Sound is great, no CEL, power and fuel economy are still there.
Really...??? A badly tuned chainsaw. ( I couldnt keep my mouth shut on this one). I guess my truck must really sound like **** huh? And I am pulling 15-16 mpg city.
 
Reply
Old Sep 22, 2008 | 03:44 PM
  #14  
preppypyro's Avatar
preppypyro
FTE Legend
20 Year Member
Liked
Loved
Community Favorite
Joined: Aug 2004
Posts: 37,887
Likes: 20
From: North Central Rural Sask.
When i had my 97 I pulled the cats off of it. There is a huge increase in sound if thats what you are looking for. (it does make a guy wonder when it does get louder, is that really restricting some exhaust flow?)

I noticed slight improvements with performance and mileage but it wasnt anything huge.

I never have the check engine light come on either.
 
Reply
Old Sep 22, 2008 | 04:59 PM
  #15  
4literranger485's Avatar
4literranger485
New User
Joined: Sep 2008
Posts: 16
Likes: 0
From: California City, CA
if you want more sound just cut off the 10 foot long tailpipe after your muffler and do a simple turndown, that pipe has a million restrictive bends in it anways. get a lot more sound out of your truck, less weight, and you're still emissions legal (well maybe not noise emissions)

and if you're real into hillbilly style....do the straight pipe instead of the muffler. but that would be loud as sh#t!
 
Reply



All times are GMT -5. The time now is 01:57 AM.

story-0
10 Ways Ford is LOSING to the Competition

Slideshow: 10 ways Ford is losing to the competition

By Joe Kucinski | 2026-06-15 09:52:01


VIEW MORE
story-1
Top 6 Best Deals Available on New Fords & Lincolns Right Now

Some great targets in today's expensive world.

By Brett Foote | 2026-06-15 09:35:19


VIEW MORE
story-2
This Hennessey Takes the Expedition Tremor's Off-Roading Capability to the Next Level

Slideshow: The VelociRaptor Expedition gains a lift, upgraded suspension, Brembo brakes, and trail-ready equipment while retaining the stock 440-horsepower EcoBoost V6.

By Verdad Gallardo | 2026-06-12 11:01:55


VIEW MORE
story-3
Top 10 Fords at 2026 Carlisle Ford Nationals

Slideshow: Top 10 Fords at 2026 Ford Nationals

By Joe Kucinski | 2026-06-09 11:10:08


VIEW MORE
story-4
3 Best / 3 Worst Parts of Modern Ford Ownership

Based on years of owning multiple modern Ford products.

By Brett Foote | 2026-06-09 10:53:36


VIEW MORE
story-5
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches

SPONSORED: From muddy boots to rain-soaked cargo, these upgrades address some of the most common frustrations Ford truck owners face every day.

By Pouria Savadkouei | 2026-06-08 18:50:34


VIEW MORE
story-6
Every 2026 Ford Engine Explained

Here's everything you need to know about every Ford engine available for the 2026 model year.

By Brett Foote | 2026-06-05 12:58:01


VIEW MORE
story-7
10 Ugly Ford Trucks That We Still Kinda Love

Slideshow: 10 ugly Ford trucks that we still kinda love.

By Joe Kucinski | 2026-06-03 09:51:16


VIEW MORE
story-8
10 Things Every Truck Owner NEEDS (2026 Edition)

Slideshow: the best gifts for dads & grads

By Michael S. Palmer | 2026-06-03 15:43:58


VIEW MORE
story-9
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath

Slideshow: Called the Fortress, the 850-horsepower pickup combines Raptor underpinnings with military-inspired features, survival equipment, and a starting price of $285,000.

By Verdad Gallardo | 2026-06-03 11:38:36


VIEW MORE