Newbie returning back after some advice

[ommis]

hi guys I have a 40d m sport and I need to know what the engine code is 24/03/2011 . reason being I am after a new exhaust system from the cat back . the centre box sounds like its full of bits when it gets warm and rattles away . I've looked on eBay at the stain less steel systems but not sure which one to get . any advice would be much appreciated.i even thought of cutting the centre box out and put some stainless tube in its place . but no one stocks the size I need .

[Werke23]

Have the same 40d 12/2011
Engine code of mine is N57D30B