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WARNING: This page is about a different car, the 2001 Saab 9-3. However, it is still accessible from the selected car via links, so may be relevant.

General condition for this diagnostic trouble code: Atmospheric pressure must exceed 72 kPa as well as coolant and intake air temperature must exceed -70°C.
Engine running. Closed loop blocked in rich or lean position during a number of combustions to maintain the voltage from the oxygen sensor 2 at 0.6 V. Number of required combustions is adapted.