I have a buddy with an 02-03 Super Duty with the gasoline V8 (no idea on the size) and we were wondering if there is a way to remove the stock kitty. It's got the O2 sensor before and after the cat, so I was to understand that you can't do it, but I've heard of people who have and was wondering if and was wondering if anyone here knew how....thanks guys!

 

Don't know about the cat, but he's got a 5.4L (it's the only V8 for these rigs).

 

Try this...http://www.mkiv.com/techarticles/oxy...sor_simulator/


Why are you removing the cats? I sense Bear River will jump onthis one, he's the cat guru.

 

There should be no O2 sensor after the cat, I have an 02 w/ a 5.4 and my buddy has a 03 w/ a 5.4 neither has an O2 sensor behind the cat. It just needs a pipe in place of the cat if your serious about doing it.
Some people have removed it and noticed a slight difference (both an increase in performance and exhaust tone) but most say that it's big enough and doesn't restrict enough to bother it. I asked about doing this in the V10 forum (same exhaust) and most everybody that replied strongly suggested that I keep it on.

 

He wants the bigger sound and more performance. This truck will never have to go through an inspection, so that is not an issue...

that link didnt work for me WeWonIt

 

You won't really gain any performance if the cat isn't plugged. Converters have come a Looooooooooooooooooooong way since they started putting them in. If you want more sound, replace/remove the muffler.

 

http://www.mkiv.com/techarticles/oxy...sor_simulator/
Try this one?
I don't condone cat removal, but if you do you'll have to fool his computer.

 

I'm telling you from experience, you gain nothing but noise.

 

thats what he wants, its already straight piped post-cat, but he wants it louder

 

glass packs could make it a bit louder....or he could get some headers

 

FOOLISH destined for nothing but headaches and tickets, but just my opinion

 

Nice thing about America, everyone is allowed to have one

thanks guys, I think we got the answer

 

Agreed. Just a candidate for the local sheriff.

 

If you went with a smaller converter, you can get more noise and more power. The factory cat is capable of a lot of flow, but is so large that it also creates a lot of internal drag. Under throttle, the size of the cat does bog down the engine slightly. Under light throttle it overcools the exhaust. Our 3" HD cats let a lot more sound through, are powerful enough to satisfy the rear O2 sensor. And it produces a healthy increase in exhaust temperature and velocity, which is good for power.

As far as the rear O2 sensor is concerned, some models have it, it depends on the rated weight of the truck, and whether or not the truck is designed for the California market. But if you have one, you cannot easily bypass it without a tuner. And if you get rid of some of the factory equipment, it reduces the vehicles resale value, and you can get ticketed if you drive through certain areas. I'm not familiar with your area, but I know there are places in Washington and Oregon, that will ticket you if someone reports smelling your truck, or if it is too loud. Sometimes if you get pulled over in some areas, you will meet a really obnoxious cop that will check to see if you have a cat, and he can add that to the fine.

I wouldn't take the chance. I do everything legal, and my Mazda is registered in a non-smog area. It has cats and all the other smog equipment. It really doesn't gain anything to remove them, in most cases you loose some power in the lower to mid part of the power range, the part where you do most of you driving. And the fuel economy often drops. The cat is not simply a restriction in the exhaust, it has become an important part of the system. The engines are designed to count on the induction they create.

 

So it is possible to replace the stock cat with this smaller version? I would love to get a price on it to put it past the boss. Any change in MPG with the smaller one?