gimmel1

i want to cut out my cats but am worried about the truck runnin bad or not at all. Does any one know how to do this, and not hurt the truck

otto457

Good day gimmel1,

First I have to ask some questions and give the customary warning. Are you removing all four cats or just two? Are you doing this for sound or power, or both?

-If you remove all four and you get caught running catless it is a hefty fine. The government doesn't want you putting all your exhaust fumes straight into the air and can impound your vehicle along with the fine and worse. There now that I've taken care of the warning from big brother down to business.

If you are doing this for sound/power or power you will need a custom tune from a reputable device and tuner for the truck to run at it's best level. That being said the gains will be minimal since the cats cause little (about 2 psi) interference with exhaust flow. The truck may run alright if you are doing it for simply sound but I advise against it without a proper tune. Hi flow cats would be close to the same sound while still being legal and not messing with the O2. However, there is a way to run without cats and keep those trouble codes away. If you are not putting headers in replace the area where the cats would be with 2.5" piping. Here is a link to the Gott's O2 mod. He runs long tubes and no cats without a CEL and is also correctly tuned. http://www.f150online.com/forums/exh...-mod-pics.html
Hope this answers a few for your questions.

otto457

gimmel1

well there are no inspections in oklahoma so no prob there but what i really wana do is put in high flow cats and eliminate the second o2 for ease of install and cleanliness

Fordtrucktexan

I have magnaflow high flow cats on my truck and maybe the stockers were in bad shape but I noticed a good bit of difference in better gas mileage and low end. Can't say much for sound because I had a flowmaster 40 series with dumps put on at the same time (replacing an Imco with dual 4" chrome tips)

Robsdad0312

Thats what i have been thinking about for weeks now is removing the back two cats completely. I don't want codes. Can i just cut them out and be ok? Is there something special i can do to make sure there is no CEL. Please help i am about to give up. I just want it for sound and a little better top end.

kookookachew

Well I'm bummed. I just read the article from the link and found out that my LEV sticker actually means something. Apparently I can't just gut the rear cats with no CEL, I'll have to do the Gotts O2 mod.

Fordtrucktexan

I remember back in the fordtruckworld.com days everyone just cut their cats and ran o2 eliminators... I take it those aren't a viable solution anymore?

otto457

Good evening gentleman,
To gimmel1 and Robsdad0312,

The front cats do pretty much all the emissions work so you can do two different things.
1) eliminating the rears (That is if your fronts are healthy enough.)
2) replace all 4 cats with 2 high flows and remount the rear O2s behind the new cats

Both of these can be done with simply reinstalling the rear O2 or doing the Gotts O2 to ensure no CEL. Take these with a grain of salt because exhaust leaks and other problems can also turn on the CEL. Even reinstalling the rears can throw a code on some trucks. The rear O2s simply monitor cat function and do nothing as far as performance and air/fuel mix so there is really no harm to the trouble code if it is your back O2s. If you want to totally eliminate the second O2s a tuning device will be your best bet to turn them off. I don't have experience with simulators at all so I'll refrain from them.

Fordtrucktexan
Results may vary. If you feel it helped your truck, more power to you (pun intended). Every vehicle is different and other mods affect things too. It does slightly help with freer exhaust flow so it does have some effect.

otto457

gimmel1

does anyone have the linkfor the gotts o2 mod much appreciation

gimmel1

ok im retarded i saw it up in the other post dee dee dee