I know its been asked but no clear answer ive searched for a week and not found a clear one.

03 4.6 motor 4 cats. O2 in the rear cats. I see videos of catless f150s i wamt to remove my rear ones or both but dont want motor codes or to spend a 1000 bucks on exhaust.

Also im goin to do saleen style out the side before the rear tire tips. Do i have to have an x pipe before my mufflers in order to get that deep rumble like the mustang or just run true to 2 mufflers?

 

No suggesions?

I was thinking cut both cats add 1 universal magnaflo hi flo cat on ea side. That is if i have to. Of course remounting my o2's after the new cats. The. 2.5" to a offroad x pipe then to either 2 slp loud mouth ll's or 2 flow masters. Then both out the side in front of the rear tire "saleen style".I can get all than for around 200-250 then installation fees

Only thing questionable is if i really need hi flo cats or could i just run it straight and retap the o2's in the new pipe and not throw a cel? Its a difference of 85 bucks if i dont have to get the cats

 

If you remove the cats, installing an o2 sensor downstream will still set a code. The downstream 02 sensors are used to monitor cat efficiency. It needs to produce a signal that's different than the front sensor. In other words it can do almost anything except mimmick the front sensor. Without cats this is what will happen.

 

Ok well looks like magnaflow hi flows. Hows the rest of my setup sound? X pipe and either of those mufflers?