I drive a 97 f150 with the 5.4 if i have both cats removed but leave the resinators will it affect anything at all

 

i don't think it will give you any problem... i did the opposite with an '02 i took the resonators and mufflers out and left the cats. it didn't do anything. i know plenty of people who run them with nothing at all and they haven't had any problems.

 

wont do anything, just set a CEL... and smell really bad. Just cut all 4 off and buy 2 high flows, it will burn cleaner, sound awesome, and wont set a CEL...

 

will it not make my truck run ruff if i dont put nothing back under it

 

my diesal ran fine and there trucks seem to run right... you have to put a smaller pipe in where the cats were so that it will give you back pressure. just thought of that sorry.

 

diesels didn't have a downstream o2 sensor. if you remove 2 of the 4 it will be fine. if you remove all of them you need a 1/4 ohm resistor in the signal wire on the downstream o2's and it will be fine. i also reccomend just replacing all 4 with 2 high flows i have no cats and i would like to add 2 high flows when i get the money

 

what is the purpose of removing 2 of the 4 cats? any increase in performance or just sound?

 

Well yes and no, yes it will be fine, but just want to make sure you arent thinking of daily driving a truck running open manifolds, and no pipes....

Cool! So the O2 sim is just a resistor?

 

On a stock truck, or one with just an intake, I dont see how cutting the cats will help much. You might get 2-5 hp, but that is not going to really make a differenece.

Just an FYI, it is a federal offense to tamper with the emissions system on a pollution controlled vehicle. Why risk it for such a small gain?

 

1. Your truck will run exactly the same with or without cats.
2. You will get a check engine light without cats.
3. Your gas mileage will not go down without cats.
4. Your power will not go down without cats.
5. Your exhaust will smell like raw fuel without cats.
6. You will have to turn your truck off at drive thru's or any time your window is down to keep from stinking yourself out. (just like a diesel)
7. Your truck will be louder, both inside, and outside the cab.
8. A set of mil eliminators (under $20 or make them yourself) will fix your check engine light.
9. You will probably regret cutting them off. But maybe not.


Nope. That will not work. You have to have an RC circuit. I'll post a link on how to make one tomorrow.

 

I noticed more torque, and more top end (hp) power.... and i did it to where you would have to take the heat sheild off of the cat just to even get a glimpse at the top side of the cat where i gut a small window out.
-Patrick

 

Mine are gone. A piece of pipe in their place.. Oh well, the CBI will get me soon. (catalyst bureau of investigation)

 

yah eventually ill cut them back open and run a pipe through the middle of the housing, for even better flow characteristics, and the exaust wont "pop" as much when i rev, or coasting. (not that its obnoxious now)

 

Yeah, My precats were intact until a few weeks ago. I gutted them, and now it has that "header ring" to it.

 

thanks for all the great advise the main reason i wanted to cut them off is because i think the right cat is getting stopped up its makin a funny noise and plus were im from everyone drives chevy's and rag my ford cause it aint as loud but i still pull of and leave them in the dust everytime