Cold air intake

[j.fro]

Funny, no one's really answered your questions. If you install an aftermarket intake and filter, it's most likely that the filter is oiled. It is a known fact that an over-oiled filter can foul the mass air flow sensor, and this will cause the CEL. The Porsche ECU has no problem adjusting for any greater airflow gained by adding an aftermarket intake/filter. Yes, there can be an HP gain with a higher flowing filter/intake, but there are certainly things to consider.
Generally, HP gains made by swapping stock parts for aftermarket parts will cost you in street drivability/legality
...which is why I'm starting to show for a trailer (and possibly add another Porsche to the stable!)