Well, i went for the above mentioned K&N 2993, and it already makes a noticeable change! The sound is much nicer, a deeper growl instead of the usual "4-cylinder-screaming". Now the piggybank gets filled up for the Aero Racing manifold and catalyst!
@Rog: if I attach a cylindrical filter directly on top of the TB I will "skip" the mass air flow sensor, and I don't think the ECU will like that... Well, maybe the MAF just needs to be moved
