Diagnosis conditions

Oxygen sensing system active
No secondary air diagnosis
Air mass < 30 kg/h
Engine running
Vehicle speed = 0 km/h
Intake air temperature between 5° C and 50° C
Engine starting temperature between 5° C and 55° C
Battery voltage > 11 V
Engine load <= 30 %
Altitude correction factor > 0.75
EVAP canister burden < 3
Time elapsed after engine start-up > 990 seconds or mixture adaptation completed
No faults in: Throttle position sensor, idle air control, vehicle speed, EVAP canister purge valve, mass air flow sensor, voltage supply, pressure sensor, shutoff valve and engine temperature

NOTE: Fuel tank ventilation diagnosis is initiated with the Porsche System Tester 2 in the "Short test" menu. This reduces the time elapsed after engine start-up to 30 seconds.

If the diagnosis does not run, give a short acceleration burst.

Fig 1: DTC P0442 Fault Conditions

Courtesy of PORSCHE OF NORTH AMERICA, INC.

NOTE: The EVAP canister purge valve is very sensitive to contamination. If the lines to the EVAP canister have to be detached, the outside of the canister must be cleaned beforehand.