I'm looking at buying a used stock exhaust for my 400ex so I can work on it in my back yard without pissing off the neighbors (the racing exhaust is just too loud since I live in a urbanized area). I have a 2001 model, and I've been looking around at others. I found an exhaust from a 2004 model for relatively cheap. My question is, are those pipes similar(or the exact same) enough for me to put on my 2001? Thanks in advance.