911 Carrera 4 Cabriolet (996) F6-3.4L (1999)
Air Injection Control Valve: Service and Repair
Replacing Anti-run-on Valve For Secondary Air
If the anti-run-on valve or the check valve are defective, the secondary air system must be converted to the system used as of model year 2000, see
Carrera Technical Information 1/02 2669. A list of new or omitted parts is attached to the aforementioned Technical Information document.
Diagram Of Secondary Air Injection Up To Model Year 1999