HELLO, I HAVE TROUBLE CODES PO330,PO340, ON MY OBD2 READER WITH THE MAINT LIGHT ON IN 96 BMW Z3 ROADSTER 4CYL., PO330 IS KNOCK SENOR, PO340 IS CAMSHAFT POSITION SENOR, I WANT TO KNOW HOW TO FIX THEM BOTH. WHERE ARE THESE SENORS LOCATED?

The Cam Position Sensor is a common item to fail. However, the cam positioning mechanism can fail too giving that code.

There are two sensors and the Exhaust Cam Sensor is most common to fail. I always replace both.
Te CKP's are on the top front of the engine next to the cylindrical operation solenoids.

Knock sensors fail too and need checked or correct feedback to ECU with a scanner.
Find a shop near you at http://www.iatn.net/shopfinder/

These engines require regular oil changes with quality synthetic oils and OE filter....not a FRAM or WIX !

Buy only BMW sensors ...aftermarket have high failure rate.