What sounds good? And should I go 2.5" piping?

 

I have no idea, I dont like loud because I'm a grown up, I liked loud when I was a kid, but now I cant hear **** and want nice and quiet.
So I went to the local muffler shop when my muffler rotted out and got a SUV sized super quiet muffler, $100 installed, taxes included.

 

Would I be able to cut out the cats and leave the o2s in a 2000 disco 2?

 

when I bought mine it had a blown muffler and bad resonater, we cut it all off muffler back and installed a thrush turbo2 muffler and used some straight pipe to take up the length difference, we then reused the over the rear pipe and got a generic long tail pipe which eliminated the resonater

this was all pep boys parts think it was under $100 and diy, the rig is not loud you can hear it a little at idle but is not loud or droning going down the road like a dynomax or flowmaster

 

question, if you take the cats out then what stops the cel for bad cat efficiency?