03 z71 exhaust question

[jb034]

Im looking to put some edlebrock shorties on my 03 5.3 z71 stepside. Ive got 2 highflow cats and a di/do magnaflow and 2 18" tips. My question is how many cats do I need. Im planning on running 2.5" pipe from the headers back and have the tips both exit before the rear tire.

[oneloudz71]

You have 2 factory cats, if you were replacing them with 2 aftermarket cats I would say you probably need 2. If you don't have emmissions testing in CT then you don't really need any, but you are going to have to tune it so the 2 downstream O2 sensors arn't throwing codes all the time.

[jb034]

so how many o2 censors are in the system? and where are they?

[Rye 21]

so how many o2 censors are in the system? and where are they?

There are 4 in total.

Two are in front of the cats. These are very important, do not get rid of these.
The other two are located behind the cats. These would go if you dont run cats. These just tell the computer if the cats are doing their jod or not, which they wouldnt if you removed the cats.

[jb034]

so will the front 2 go in the headers? and can the back ones be put in the cats? the cats i have already have bungs in them

[oneloudz71]

Yes, your headers should have bungs for the front sensors and you already answered you own question by saying that the new cats have the rear bungs in them.

[jb034]

sweet! well thanks guys that should be the new setup

[jb034]

Anyone have pics of dual out the side before tire? im set on running it like this http://www.f150online.com/forums/members/ga4x4screw-albums-new+exhaust-picture156669-true-duals-straight-piped-exiting-before-passenger-side-tire-two-3-5x18in-tips.jpg just wana know if there is room for an 18" tip to run clean from the muffler out flush with the body