It's funny how everyone is commenting about their N55's catless DP when the OP drives a N54. 2 completely different style of DP's.
I live in Brea but my parents live in Fallbrook so I'm down periodically. I have BMS N54 catless down pipes. I'm not sure why members are saying catless DP's smell because I honestly haven't noticed one difference in smell, just power. Unless people removed their secondary cats and E90 resonators then I don't see what the big deal is about smell. DP's are 100% worth the money and hassle of installing /uninstalling. Crucial mod if you want more top end power.