I feel a bit dumb, but I've never taken a titanium 4 pipe apart. I'm going to a national park where it needs to be quiet and also have a spark arrestor. I'm working on getting the spark arrestor... I did buy the FMF quiet core insert... so my question. does it go in the front or the back of the canister? Thanks for all your help. Hey have any of you had a park ranger check you for a spark arrestor? how do they check stamp or stick up your pipe (so to speak). I'm going to red rock.. and not too worried about burning rocks down. But I do want to comply with the law. I was thinking about putting in a fine metal screen myself and save the money for the spark arrestor that is being sold for over $50. Any thoughts on that?