I installed Berk High flows on my 350Z over the weekend and had never done a cat install/removal. Took me 2 hours and cruised right through with no issues. My father in law has a car lift at his house though so I had great access from underneath. The Berk cats are by far my favorite breathing mod so far. It pulls harder through the whole power band now. I recommend these cats to anyone with a Z. Also no CEL issue. Thanks Berk.