I had my SV cat deleted (Before O2 Sensor) and I'm wondering if there is a difference in terms of sound and performance if I bought the arrow header instead.
Hmm is it ok to reflash ECU on the stock air filter? or should I replace it with a performance fiilterThe big improvement comes with the fuel tuning, especially in the midrange. The factories map them so lean in the mid to pass emissions, that they're barely running. As a rule, you don't gain all that much on top end power, but can see 5-6hp in the mid range. Plus you get a much smoother, better running bike all across the board once you get the A/F at 13.5:1, no matter what exhaust you have.