Have a read of these threads...

Adjust CO - http://www.xt660.com/showthread.php?t=55

Adjust TPS - http://www.xt660.com/showthread.php?t=56

Removing Snorkel - http://www.xt660.com/showthread.php?t=12547

Drilling airbox - http://www.xt660.com/showthread.php?t=321

If you've got a K&N, then I'd leave it for now.

Fit the DNA stage 2/drill holes in the airbox when you have the ability to adjust the fuelling (ie: fit a Kev Mod).

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