did mine with no prob but i went the r6 header route and did a custom map...not hard to installI installed a two brothers exhaust last week and rode on it for about 5 days. Lots of crackling and popping! Not necessarily a bad thing, I just don't like it. Purchased PCV online for about $270. Easy to install. No more popping. Very loud exhaust! Looking at the map, there were plenty of changes all throughout. Power has noticeably gone up!
If you want to save $ for the time being, modify the stock exhaust for less than $100. You'd have to replace it later anyway should you go TBR or such in the future. To get the best HP performance first mod to do is the exhaust. Then the debate is between air or ECU for 2nd but they seem to go hand in hand. (Then you dial in the suspension!)I'm wondering what kind of power gain is possible without changing the exhaust. I don't want (have the money) to change the exhaust as of right now. Just curious what others have done and their results.