F150online Forums - keep it single or duel

I was talking to a friend today who has his own preformace shop, and he recomended I forget duel pipes and stay with a 3" single pipe into the muffler and out.

one of the reasons for this was that he said the O2 sensors will work better than they would on a duel pipe set up, has anyone else heard this? also I have the raven z33 right now and it is still way to quiet.. boy and I glad I didn't put a z55 on it would have barly been louder than the stock muffler.

now to make my 33 a bit louder is it possable to take out only one set of Cats? so instead of 4 cats I would only have 2.. how much would this increase the noise?

thanks
Steve