(For pre '08 XB's) - Normally, anything above doing either the exhaust or intake upgrade requires soemthing to be done to the ECM. You can squeak by with both mods if you flash in Race settings to your ECM. It would be rideable, just not optimal. To get full benefits, you'd need a custom tune to your setup through some datalogging.If I remember right I read , (I think in this) that with a pipe mod and k&n isn't that a ecm retune isn't completely necesary because it will "relearn" and readjust to the new set up by running in closed loop?