I'm sure I'll be corrected if I'm wrong, but this is my understanding of Anti Lag and 2 Step. Anti Lag is a system that retards timing. Creates explosions in your exhaust manifold spinning the turbo up. It will significantly decrease life of Exhaust manifold, turbo and exhaust. 2 Step is a system that cuts spark in the engine, while still having fuel injected. When the spark then hits, it ignites the excess fuel which again, will create an explosion spinning up the turbo. The noticeable difference, is that Antilag is a LOT louder. Loud to the point where even if you're expecting a few loud explosions, it still makes you jump out of your skin. 2 Step is more of a rev limiter where as Anti Lag is like, something else....?