if i were to take of the cats on my expedition 5.4l would that mess anytihng up or make the cel go on. and if so ive heard of something that you can plug into the oxygen sensor to correct this.? is that right

 

Why do you want to remove your cats?

Anyways, I think on newer vehicles it'll turn on your check engine light or something like that. And mess with the fuel curve because the computer won't be reading right. IMO you should get a Catco cat because they are hi-flow and legal.

 

Repalce them with 2 high flow cats or there might be a mil eliminator for the O2s that are after the cats.(DO NOT hook these to the ones before the cats ithat will screw up the computer) It shouldn't affect the fuel curve though. As for your offset question, are the inlet and outlet on the stocker both offset from each other or does one appear to be centered on the muffler?

 

there in the middle nut i cant find any high flow cats, but i looked underneath there and couldnt i just get rid of the last cat?
and it would be louder

 

Yup, it will help some.