I have an '06 C90 that I had the air injection system removed from, removal kit is $25. It was pretty easy, I had a local mechanic do the work and it took him no time at all. It gave me faster throttle response, got rid of that fake air breather on the right side of the engine, and improved my fuel mileage a few more mpg!

Thought my other C90 riders might like to look into this as well. I also like the look without the fake air filter container too!