just got an "06 f4i and was mildly surprised to find a cat & 02 sensor. this is a 49 state bike bought in tx. anybody know when they started putting cats on f4i's? are slip-on pipes available with fittings for the o2 sensor? i would like to put a pipe on for two reasons. first, a little more sound. secondly, to have a quicker cooling pipe. i have to park outside and use a cover. the stock can stays too hot to cover without melting for 20 min. had aftermarket cans on other bikes that cooled quick. any thoughts you have would be good to hear.

 

check out the d and d pipe, i think the part # is 450-14a,for the ca model bikes w/ o2, but should work in your case, w/ the cat and o2. its a polished stainless/aluminum pipe. looks very nice, but tends to be on the louder end of the spectrum.

 

sorry, a quick thought, check out pipecity.com, pretty decent prices, and selection from what ive seen.