09 fx 4x4
 

I have a o9 fx 4x4 ordered. I read in this forum that a k/n airfilter will increase performance and hp. I plan on purchasing one. Any other suggestions to tweak performance would be appreciated. thanks

Really not going to get you a noticeable amount of HP and performance. Get a chip/programmer for anything substantial.

instead of using the K&N cotton gauze filter get an AEM dry foam unit to keep from getting your MAF all dirty. Bamachips.com for your tuning needs.