tuning? is it worth it?
How will you gauge performance gains? No dyno, I'd tend to wait and get a professional dyno tune.
Also, tuning software, wideband O2, and cables will run you well over 500 bucks anyways... and then you till have to learn how to use the software, and not blow anything up in the learning curve...
Oh and get rid of the shitty K&N filter and go back to a regulr paper filter. The K&N takes oil which goes through the intake duct and coats the MAF wires, which will cause fueling issues which will lead to codes being thrown nd your car running bad.

