Notices
1999 - 2016 Super Duty 1999 to 2016 Ford F250, F350, F450 and F550 Super Duty with diesel V8 and gas V8 and V10 engines
Sponsored by:
Sponsored by: Real Truck

Remvoing Cat, Straight Pipe?

Thread Tools
 
Search this Thread
 
Old Mar 27, 2011 | 08:02 PM
  #1  
Kim's Hipster's Avatar
Kim's Hipster
Thread Starter
|
Cross-Country
10 Year Member
Liked
Joined: Feb 2011
Posts: 83
Likes: 6
From: Sacramento CA
Remvoing Cat, Straight Pipe?

Hey guys,

As some may know, my cat is not the right one for my truck. I am going to have to buy a new cat in about a year and a half, so I can pass smog here in CA. For now though, I have a question.

Will the service light come on if I cut the cat out and just run a straight pipe? It comes on now I think because of the wrong cat. It's to small. I am hoping to solve the light problem by putting a straight pipe on it for now. What are some of the cons' of taking the cat off and not replacing it? For now that is.

If not, no big deal, just means I will have to use my new code reader to turn the dumb thing off every so often! LOL
 
Reply
Old Mar 27, 2011 | 08:05 PM
  #2  
redford's Avatar
redford
FTE Leadership Emeritus
25 Year Member
Liked
Loved
Community Favorite
Joined: Sep 2000
Posts: 23,174
Likes: 1,678
From: Stephensville WI
Club FTE Gold Member
No, you won't get a Service Engine Soon or Check Engine Light if you put a straight pipe on a 7.3L diesel.

Now, a 6.4L or a 6.7L you will have an issue, but on the 7.3L and 6.0L you'll be OK.
 
Reply
Old Mar 27, 2011 | 08:36 PM
  #3  
Bigpipes 35's Avatar
Bigpipes 35
Cargo Master
10 Year Member
Liked
Loved
Joined: Feb 2011
Posts: 3,450
Likes: 13
From: Forest lake minnesota
Not sure that it matters but I think she has a v10
 
Reply
Old Mar 27, 2011 | 08:37 PM
  #4  
Kim's Hipster's Avatar
Kim's Hipster
Thread Starter
|
Cross-Country
10 Year Member
Liked
Joined: Feb 2011
Posts: 83
Likes: 6
From: Sacramento CA
Originally Posted by redford
No, you won't get a Service Engine Soon or Check Engine Light if you put a straight pipe on a 7.3L diesel.

Now, a 6.4L or a 6.7L you will have an issue, but on the 7.3L and 6.0L you'll be OK.
Oops, forgot to put it is a 1999 F350 V10 SD. My bad!
 
Reply
Old Mar 28, 2011 | 12:32 PM
  #5  
Pappy1911's Avatar
Pappy1911
Senior User
Joined: Oct 2010
Posts: 119
Likes: 0
Just sayin'

I think it is against Federal/State law to remove the cat for street use....
 
Reply
Old Mar 28, 2011 | 01:37 PM
  #6  
Fosters's Avatar
Fosters
Fleet Mechanic
Joined: Aug 2006
Posts: 1,684
Likes: 0
From: Phoenix, AZ
Trucks sold originally in california had to have an 02 sensor after the cat to monitor the efficiency for obd2 compliance; trucks sold everywhere else (250s and 350s that is) do not have an after cat sensor, so they would not know whether the cat is acting normal or not. Get underneath and see if you have a sensor, that'll answer your question. If you don't have a sensor, you can go ahead and do it, if you have one, stop by autozone and have them check the code(s) thrown. You can turn off the 2nd sensor in a tune, or you can run an eliminator that tricks the computer (nothing more than a resistor wired in to an extension for the o2 sensor). I don't know where you can buy those anymore or where you can get the components to make one though...

If you ask me, life was better before catalytic converters... One less expensive pos part to rob you of power, mpg, and to get clogged up...
 
Reply
Old Mar 28, 2011 | 04:21 PM
  #7  
2003 f-250's Avatar
2003 f-250
Senior User
Joined: Mar 2011
Posts: 161
Likes: 1
From: ohio
the p.o. was kind enough to remove the cat from my 03 f250 and I wish that they wouldn't have. It is just loud and has an obnoxious tone/cackle to it, not like the old v-8's. I don't care what people say, as long as the cat is in working order it will not rob you of any noticeable hp or mpg because the friggin thing was design to run with it.
 
Reply
Old Mar 28, 2011 | 04:43 PM
  #8  
Fosters's Avatar
Fosters
Fleet Mechanic
Joined: Aug 2006
Posts: 1,684
Likes: 0
From: Phoenix, AZ
Originally Posted by 2003 f-250
the p.o. was kind enough to remove the cat from my 03 f250 and I wish that they wouldn't have. It is just loud and has an obnoxious tone/cackle to it, not like the old v-8's. I don't care what people say, as long as the cat is in working order it will not rob you of any noticeable hp or mpg because the friggin thing was design to run with it.
It may have been designed to run with it, but so have all of the newer diesels and their MPG/power robbing emissions controls. On my mustang removing all 6 of them *******s made a big difference at the track (weight savings alone made a difference), on my jeep the power gain is noticeable... I told myself I'll keep the X quiet, and keep finding reasons not to take it off, but if I can't figure out my low mpg woes (how I came upon this thread), I'll be hacking it off soon enough, as it may be plugged... And there's no way I'm paying 800 bucks for a new one.
 
Reply
FTE Stories

Ford Trucks for Ford Truck Enthusiasts

story-0

10 Things Every Truck Owner NEEDS (2026 Edition)

 Michael S. Palmer
story-1

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

 Verdad Gallardo
story-2

Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer

 Joe Kucinski
story-3

2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)

 Brett Foote
story-4

Top 10 Ford Truck Tragedies

 Joe Kucinski
story-5

AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make

 Brett Foote
story-6

Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!

 Michael S. Palmer
story-7

Ford's 2001 Explorer Sportsman Concept Looks For a New Home

 Verdad Gallardo
story-8

10 Best Ford Truck Engines We Miss the Most!

 Joe Kucinski
story-9

2026 Shelby F-150 Off-Road: Better Than a Raptor R?

 Brett Foote
Old Mar 28, 2011 | 04:44 PM
  #9  
MachDream's Avatar
MachDream
New User
Joined: Mar 2011
Posts: 21
Likes: 0
Originally Posted by Kim's Hipster
Hey guys,

As some may know, my cat is not the right one for my truck. I am going to have to buy a new cat in about a year and a half, so I can pass smog here in CA. For now though, I have a question.

Will the service light come on if I cut the cat out and just run a straight pipe? It comes on now I think because of the wrong cat. It's to small. I am hoping to solve the light problem by putting a straight pipe on it for now. What are some of the cons' of taking the cat off and not replacing it? For now that is.

If not, no big deal, just means I will have to use my new code reader to turn the dumb thing off every so often! LOL
I have a 5.4 and i removed the cat and replaced with strait pipe. on mine, not sure on the V10..but there is no 02 sensor after the cat so no issues.
 
Reply
Old Mar 28, 2011 | 05:53 PM
  #10  
2003 f-250's Avatar
2003 f-250
Senior User
Joined: Mar 2011
Posts: 161
Likes: 1
From: ohio
Originally Posted by Fosters
It may have been designed to run with it, but so have all of the newer diesels and their MPG/power robbing emissions controls. On my mustang removing all 6 of them *******s made a big difference at the track (weight savings alone made a difference), on my jeep the power gain is noticeable... I told myself I'll keep the X quiet, and keep finding reasons not to take it off, but if I can't figure out my low mpg woes (how I came upon this thread), I'll be hacking it off soon enough, as it may be plugged... And there's no way I'm paying 800 bucks for a new one.

It's your vehicle and do as you please. I am telling you that cat's on these newer trucks aren't as restrictive as you lead them on to be. If we were back in 1980 then I'd agree 100% to get rid of them. That muffler that's three feet long will restrict more than the cats do. The cats on the diesels are not the same as what's on this guys' truck. Now that we mention the diesel exhausts, they are not even close except for the fact that they make the vehicle meet emissions and make it quieter.
 
Reply
Old Mar 28, 2011 | 05:54 PM
  #11  
2003 f-250's Avatar
2003 f-250
Senior User
Joined: Mar 2011
Posts: 161
Likes: 1
From: ohio
oh, btw.....the emissions standards for 3/4 and 1 ton trucks are completely different than your mustang and jeep.
 
Reply
Old Mar 28, 2011 | 06:59 PM
  #12  
lorilam's Avatar
lorilam
New User
Joined: Mar 2011
Posts: 2
Likes: 0
Can anyone tell me how to post a question??? thank you first time using
 
Reply
Old Mar 28, 2011 | 07:03 PM
  #13  
lorilam's Avatar
lorilam
New User
Joined: Mar 2011
Posts: 2
Likes: 0
I have recenetly bought a 350 and am hauling rvs with it,,, put the bigger exhaust ,,,and chip in it and air intake ,, but I am still only getting 13 mpg empty and loaded average,,, what else can I do to get the better mileage otherwise i will be parking the truck !!!thank you
 
Reply
Old Mar 28, 2011 | 07:20 PM
  #14  
Kim's Hipster's Avatar
Kim's Hipster
Thread Starter
|
Cross-Country
10 Year Member
Liked
Joined: Feb 2011
Posts: 83
Likes: 6
From: Sacramento CA
Yah, this is a CA truck in CA. I know it is illegal to not have a cat, but we were only going to run no cat till we had to smog it again in a year and a half. We were just thinking that the cat on it now is to small and restricting, so if we just ran straight pipe, it wouldn't be restricting it. I just don't want the to small of a cat to do damage to my trucks engine because it gets to hot or something.

We don't have the 2+ grand to buy a new cat right now.

I do think it has the sensor behind the cat too. I will have to double check though.

My tranny guy turned the light off when he cleared the codes. It stayed off till I ran down the freeway. Then it came back on. I got home and turned it back off with my new code reader. That is when I thought of putting the straight pipe on. Even if it (straight pipe) doesn't keep the light off, would it be better to go with no cat, or keep a to small of cat on it?


As far as posting a new question. Go to the sub forum you want to ask in, for example, SuperDuty & Heavy Duty. Then inside that forum click on "New Thread". That will open up a spot for you to type your question in! Hope that helped?
 
Reply
Old Mar 28, 2011 | 08:36 PM
  #15  
KOESTNER's Avatar
KOESTNER
FTE Legend
Joined: Apr 2010
Posts: 127,357
Likes: 3
From: Peoria, Illinois
Originally Posted by Kim's Hipster
Yah, this is a CA truck in CA. I know it is illegal to not have a cat, but we were only going to run no cat till we had to smog it again in a year and a half. We were just thinking that the cat on it now is to small and restricting, so if we just ran straight pipe, it wouldn't be restricting it. I just don't want the to small of a cat to do damage to my trucks engine because it gets to hot or something.

We don't have the 2+ grand to buy a new cat right now.

I do think it has the sensor behind the cat too. I will have to double check though.

My tranny guy turned the light off when he cleared the codes. It stayed off till I ran down the freeway. Then it came back on. I got home and turned it back off with my new code reader. That is when I thought of putting the straight pipe on. Even if it (straight pipe) doesn't keep the light off, would it be better to go with no cat, or keep a to small of cat on it?


As far as posting a new question. Go to the sub forum you want to ask in, for example, SuperDuty & Heavy Duty. Then inside that forum click on "New Thread". That will open up a spot for you to type your question in! Hope that helped?
I couldn't see 2k for a cat so got a Magnaflow universal hi-flow cat for IIRC 169 bucks free shipping. Can't remember from who but check around.
 
Reply



All times are GMT -5. The time now is 08:43 AM.

story-0
10 Things Every Truck Owner NEEDS (2026 Edition)

Slideshow: the best gifts for dads & grads

By Michael S. Palmer | 2026-06-02 21:45:57


VIEW MORE
story-1
Rezvani's Latest Post-Apocalytic 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 | 2026-05-30 18:33:59


VIEW MORE
story-2
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer

Slideshow: 10 most expensive Ford trucks ever sold on Bring a Trailer.

By Joe Kucinski | 2026-05-27 16:24:34


VIEW MORE
story-3
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)

Here's everything that has changed for the latest model year.

By Brett Foote | 2026-05-27 16:17:28


VIEW MORE
story-4
Top 10 Ford Truck Tragedies

Slideshow: Top 10 Ford truck tragedies.

By Joe Kucinski | 2026-05-18 19:34:33


VIEW MORE
story-5
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make

And it might be even better than that.

By Brett Foote | 2026-05-18 19:26:42


VIEW MORE
story-6
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!

Slideshow: Does lowering an F-150 Lobo RUIN the ride quality?

By Michael S. Palmer | 2026-05-18 19:20:37


VIEW MORE
story-7
Ford's 2001 Explorer Sportsman Concept Looks For a New Home

Slideshow: Ford's bizarre fishing-themed Explorer concept has resurfaced after spending decades largely forgotten.

By Verdad Gallardo | 2026-05-12 18:07:46


VIEW MORE
story-8
10 Best Ford Truck Engines We Miss the Most!

Slideshow: The 10 best Ford truck engines we miss the most.

By Joe Kucinski | 2026-05-12 13:09:47


VIEW MORE
story-9
2026 Shelby F-150 Off-Road: Better Than a Raptor R?

Slideshow: first look at the 810 hp 2026 Shelby F-150 Off-Road!

By Brett Foote | 2026-05-12 12:50:07


VIEW MORE