camshft position sensor.
 

who can help me find this little buddy.

I have a CEL related to this thing

This is what it looks like... And it ain't cheap.
http://www.rockauto.com/catalog/raframecatalog.php?carcode=1417913&parttype=7192&a =FRc1417913k935268
This one is for a 2003. The one for a 1999 looks similar, if not identical.

Download this file and go to page 24- D10. Items 4 and 11.
http://www.cannell.co.uk/Boxster_Manuals/986%20Group%200a%20Diagnosis%20To%2045.pdf

They are a little tricky to get to.
Bank 1 or 2? Bank 1 is a little easier than Bank 2.

Hope this helps. Good luck.

mike

its bank one.
where is that?? on the left side where the air filter is or on the right where the AOS is??

Bank 1 is the passenger side.