"L" or "M"
 

what does the "L" upgrade or the "m" upgrade do...i can't find it on the search..like i know its supppost to fix flooding and MPG, but does it give more HP or Torque or what?

use the search, and yes there are plenty of threads on that, better MPG, fix Flooding issues and yes slight HP gains

can you feel the difference?

do a search for "reflash" you should get some info