I installed HMF Muffler I got on EBay, was a return with a small scratch for half price. Love the sound! Nice deep, not glaring loud like a straight pipe. If you pop off your left side cover like you are checking the oil, you can take a flashlight and easily trace the exhaust down to the connector for the muffler. I have a 2008 GS which had no cat from BRP. VERY easy to remove and swap mufflers. One bolt on right side holding muffler, then the O-clamp & spring. Rotate old muffler up and down and it will slide right off. Easy enough to look under your bike at what you have and how to remove. I will say this - the BRP muffler weighs a TON compared to the new aftermarket mufflers. Must be the extra cat converter materials or something in there.
Once you install an aftermarket muffler you will probably start getting pops and little backfires for a while as the flow through the exhaust is much faster, making the O2 sensor feedback thinks it is too lean. I got a used electronic box that connects to the throttle body and "pads" the O2 feedback so engine runs richer. I totally am drawing a blank on the device name, hopefully someone can remember it - having an old man moment!! I did take out the air box to get to the right side throttle body connector, so while in there upgraded the plugs to the fine tip Iridiums from Baha Ron. Any-hoo after installing that runs like a bat outta you know where!
