I havent bought nothing used performance related that came with a warranty! Hell most things you buy new "performance related" dosnt come with a warranty. Be very thorough on what you buy used. Ive seen some parts and cars switch hands on here 3-4 times before it may ever get installed, does that mean the last guy is responsible for what he was told by 2-3 other sellers because they havent installed this part yet? There is only a handful of people that I would take thier word on conditions of parts, anyone else, buy at your own risk or buy new.

This is why I would never buy off e-bay used- I want to see it and inspect things myself so if I inspect it and it was junk, noone to blame but myself. Just my thoughts
I like ham