I wouldnt mess with it... I dont know about on a Banshee, but everybody I know was saying how much it helped the raptors, but mine runs better with the arrestor in then out. Even with the right map on the raptor with the arrestor out, it runs better with it in. I know that they are a lot different then a banshee, but I dont think you will notice any difference. If you want something thats going to run better, get an aftermarket set of pipes.