Ok so Im thinking about removing the cat and putting in a strait pipe. Im running an 03 Excursion 4x4 v10 6.8 4.30 Limited slip with 5star tuner CAI 3" Y-Pipe flowmaster 44's and 35" mudders. The tuner i have gives me the ability to disable rear o2 sensors. Im not worried about losing mpg (its an excursion not a prius lol) But if i gain mpg (without sacrificing power) im all for it. Anyone removed it yet and how did it turn out for yall?

Oh and we dont have emission tests around here.

 

I remember reading about removing the cat with little benefit. I can say you will get more unburned fuel smell inside without. As far as the rear 02 I believe those are only on California emissions models. Sounds like you have all the mods up to par.

 

All it does is make it stink like an 86 chrysler.... NO PERFORMANCE GAINS. All you get is the brohemian exhaust clatter... And before anyone suggests it, there is no such thing as a "hi flow" cat either, they are just underperforming cats. Have you replaced the t-pipe yet? That is a bigger choke point. And as stated above, non-cali, no rear 02. It's actually OBD-1 level programming in an OBD-II box.

 

I wouldn`t remove the cat. it will not help performance or mileage. it will stink too! but not like an 86 Chrysler more like a 70`s car before cats! an 86 Chrysler had a cat.

 

No, that's what an old Chrysler smelled like on the inside...lol

 

yep Y pipes been replaced. I had the guy at the muffler shop replace anything he saw might restrict flow with 3" strait pipe. But he wouldnt remove cats (something bout it not being legal lol)