Cat Converter
Thread Starter
|
New User
Joined: Feb 2003
Posts: 13
Likes: 0
Cat Converter
DOES ANYONE KNOW IF REMOVING THE CAT CONVERTER ON MY 1999 F250 SUPERDUTY 4X4 V10 WILL HELP IN PERFORMANCE GAINS. THERE IS NO WORRY ABOUT EMISSIONS WHERE I LIVE SO I WAS WONDERING IF IT WILL HELP. I ALSO HAVE A DYNOMAX MUFFLER ON WITH DUALS COMING OUT. ALSO HAVE POWER PROGRAMMER III TUNER.
Posting Guru
Joined: Oct 2002
Posts: 1,253
Likes: 0
From: Del Rio, Texas USA
Cat Converter
yes it will help, i used to cut them off all my vehicles when i was from WA state, they dont check, now down here in TX they do annual inspections, i wish i could cut it off, makes a word of difference.
Jetjock16
Jetjock16
Postmaster
Joined: Feb 2002
Posts: 3,496
Likes: 0
From: Calgary Canada
Cat Converter
You may want to check out this thread.
https://www.ford-trucks.com/forums/s...threadid=99144
It will likely show you a small improvement in mpg and performance, whether it's worth it or not, I don't know.
Waxy
https://www.ford-trucks.com/forums/s...threadid=99144
It will likely show you a small improvement in mpg and performance, whether it's worth it or not, I don't know.
Waxy
Posting Guru
Joined: Oct 2002
Posts: 1,253
Likes: 0
From: Del Rio, Texas USA
Cat Converter
IN ANSWER TO THE ORIGINAL QUESTON::
the question asked was how it would effect performance, not gas milage, Waxy is correct in stating the fact it might be hard to find proof of a increase in mpg as high as 2-3mpg increase..... but thats not the topic in question, as for performance any DYNO machine could easily show a cat is a 2 ft, piece of crap metal asbestos screen that kills performance, removing that thing will definatly boost horsepower to higher gains then replacing the stock exhaust with a good aftermarket setup while retaining the cat(like my setup, darn TX vehicle inspections). Anyone who knows performance engines knows CATs are no good for high output, and FORD did not use them until it was mandated by the Federal Gov., so i dont think they stuck them on their to increase engine life or effect gas milage.
RIP THAT THING OUTTA THERE, I BET IT WILL SOUND KILLER!!
you got me all exicted i may have to find a way to get ride of mine!!
Jetjock16
the question asked was how it would effect performance, not gas milage, Waxy is correct in stating the fact it might be hard to find proof of a increase in mpg as high as 2-3mpg increase..... but thats not the topic in question, as for performance any DYNO machine could easily show a cat is a 2 ft, piece of crap metal asbestos screen that kills performance, removing that thing will definatly boost horsepower to higher gains then replacing the stock exhaust with a good aftermarket setup while retaining the cat(like my setup, darn TX vehicle inspections). Anyone who knows performance engines knows CATs are no good for high output, and FORD did not use them until it was mandated by the Federal Gov., so i dont think they stuck them on their to increase engine life or effect gas milage.
RIP THAT THING OUTTA THERE, I BET IT WILL SOUND KILLER!!
you got me all exicted i may have to find a way to get ride of mine!!
Jetjock16
Senior User
Joined: Sep 2002
Posts: 487
Likes: 0
From: Hibbing, MN
Cat Converter
These maybe be a rather dumb questions, but I'm of course compelled to ask them.
T/F
The exhaust systems in these things are tuned to the computer. (Back Preasure)
If you remove that "Blockage" won't the system (computer) over compensate for the lack of back preasure.
(Remember these are questions not answers)
I live in an area too where if I took my cat off no one would ever know! I just don't want to cause more problems. (Computer or fuel system type of problems)
One more, would the OX sensor freak?
Dual exhaust would be just too cool! Just like the ole High School Hot rod!!!!
T/F
The exhaust systems in these things are tuned to the computer. (Back Preasure)
If you remove that "Blockage" won't the system (computer) over compensate for the lack of back preasure.
(Remember these are questions not answers)
I live in an area too where if I took my cat off no one would ever know! I just don't want to cause more problems. (Computer or fuel system type of problems)
One more, would the OX sensor freak?
Dual exhaust would be just too cool! Just like the ole High School Hot rod!!!!
Trending Topics
Tuned
Joined: Feb 2003
Posts: 335
Likes: 1
From: Houston, TX
Cat Converter
You could always have somebody fab you up some cutouts (speaking of the old days).
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
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
Ford Super Duty: 5 Things Owners LOVE, 5 Things They LOATHE!
Joe Kucinski
Every 2026 Ford Truck Engine RANKED from WORST to FIRST!
Michael S. Palmer
The Best F-150 Deal of Every Trim Level (XL through Raptor)
Joe Kucinski
Senior User
Joined: Dec 2002
Posts: 192
Likes: 0
From: Shamokin USA
Cat Converter
In reference to some questions posted:
Yes, you will make more pure horsepower without the cat.
No, removing the cat will have no adverse effect on the O2 sensor as long as it is not mounted in the cat.
Free-flowing exhaust is more power, but remember it moves the power band of the engine. You will get more high end power while "losing" low end power. You don't actually lose power, the rpm band of the torque curve changes.
You can step up to a high flow racing style cat. These cats offer virtually no restriction. Don't know how legal they are in Texas or the rest of the country.
Jimmie
2003 F250SD XLT SC SB 4X4
Yes, you will make more pure horsepower without the cat.
No, removing the cat will have no adverse effect on the O2 sensor as long as it is not mounted in the cat.
Free-flowing exhaust is more power, but remember it moves the power band of the engine. You will get more high end power while "losing" low end power. You don't actually lose power, the rpm band of the torque curve changes.
You can step up to a high flow racing style cat. These cats offer virtually no restriction. Don't know how legal they are in Texas or the rest of the country.
Jimmie
2003 F250SD XLT SC SB 4X4
Fleet Mechanic
Joined: Sep 2002
Posts: 1,769
Likes: 7
From: Gretna ,LA.
Cat Converter
With my setup i actually picked up power everywhere especially down low. it doesnt want to downshift as much.The exhaust system would have to be very open to lose any low-end torque.
uncorking the exhaust is a good way to build low end torque.i get no codes,runs excellent,sounds awesome.At part throttle the truck just seems to move with a lot less effort.Like i said before not everyone can remove their cat and install duals, but believe me it is sweet.When a chebby or rice burner pulls ups it is cool to see them first look at the duals exiting in front of rear wheels, then gazing at the V10 badges,it is at that point they know they are screwed!I didnt know really how good it sounded till i let my friend drive it and heard it from the outside. Hearing him catch 2nd gear chirp was cool too.
uncorking the exhaust is a good way to build low end torque.i get no codes,runs excellent,sounds awesome.At part throttle the truck just seems to move with a lot less effort.Like i said before not everyone can remove their cat and install duals, but believe me it is sweet.When a chebby or rice burner pulls ups it is cool to see them first look at the duals exiting in front of rear wheels, then gazing at the V10 badges,it is at that point they know they are screwed!I didnt know really how good it sounded till i let my friend drive it and heard it from the outside. Hearing him catch 2nd gear chirp was cool too.
Elder User
Joined: Oct 2002
Posts: 873
Likes: 0
From: Roswell USA
Cat Converter
What if u didn't want to remove the cat completely since it is illegal. Muffler shop said EPA law. Is there any considerable improvement in performance w/ an after market free flowing one? And which ones might be the leaders in the industry?
Fleet Mechanic
Joined: Sep 2002
Posts: 1,769
Likes: 7
From: Gretna ,LA.
Cat Converter
actually when i removed mine it looked unrestrictive, i could look all the way through. It just had some mesh on each end,it just didnt figure into my plans. I guess one could redo exhaust- no y-pipe, and merge into cat and split back off to 2- pipes again but that would not be true duals, but would still be better than stock.
You would still be legal.I dont know about aftermarket cats but i would think they would be pretty unrestrictive. Catco makes some.
You would still be legal.I dont know about aftermarket cats but i would think they would be pretty unrestrictive. Catco makes some.
Postmaster
Joined: Feb 2002
Posts: 3,496
Likes: 0
From: Calgary Canada
Cat Converter
V10KLZZ71S,
What other mods have you done to your exhaust system? Sounds like it's pretty extensive. Do you honestly feel that removing the cat was the biggest factor? Or do you think that even if it was in place with the other mods you've done you'd still be seeing the same or very close to the same performance gains?
I realize it wouldn't be true dual exhaust, but what if you ran 2 separate cats?
I'm not trying to start a flame war, just curious as to your thoughts.
Waxy
What other mods have you done to your exhaust system? Sounds like it's pretty extensive. Do you honestly feel that removing the cat was the biggest factor? Or do you think that even if it was in place with the other mods you've done you'd still be seeing the same or very close to the same performance gains?
I realize it wouldn't be true dual exhaust, but what if you ran 2 separate cats?
I'm not trying to start a flame war, just curious as to your thoughts.
Waxy
Fleet Mechanic
Joined: Sep 2002
Posts: 1,769
Likes: 7
From: Gretna ,LA.
Cat Converter
i think that the duals are the power builder here.I dont know how i could have kept my cat other than merging duals into the the cat ,then you defeat the purpose of dualing it out in the first place.Then i have 2 magnaflows ss mufflers that flow very well. Adding an h-pipe really did the trick. Bottom line is all one has to do is look at our stock exhaust and see it was not designed for performance,and if single exhaust was so good then you would see race cars with one pipe. You can cat back all you want and it helps some, but if you want real performance gains you have to seperate the banks. I cant wait to see what headers will do now.
Logistics Pro
Joined: Feb 2000
Posts: 3,954
Likes: 47
From: Mesa
Cat Converter
I have a "test pipe" I made for mine and it's sitting on a shelf. I took the cat off for a couple weeks and couldn't stand the noise!! Horrible loud raspy exhaust. I saw no performance gains or mpg gains. I put the cat back on and have been happy ever since. The cat is monoleth or honeycomb design(same as the aftermarket free flowing cats). You can see light through it and it has a huge cross section. Sure it may add a little back pressure but in my opinion not enough to worry about. Todays cats are much better flowing than the old pellet design of the late 70's early 80's.
Thread
Thread Starter
Forum
Replies
Last Post
98SurplusExpy
1997 - 2006 Expedition & Navigator
2
Oct 6, 2004 08:03 AM
