there aren't any chips available for the s4... the s4 uses the weber 5.9 and doesn't use a replaceable chip. either the previous owner doesn't know what's on his old bike or was giving you a line of bs. most likely the former.I got my S4 used a few weeks ago and last owner told me there is a FAST BY FERRACCI chip on the bike.
Thanks for the part numbers. I found that I have the kit plus for 2001. However I was told by a dealership that termi only sells full system but I think the one on my bike is a slip on. Anyone knows why?