Good evening to everyone, since it has been really annoying since yesterday, I turn to you. Model: Volvo 850, 2.5 20V Model Year 1997, Automatic Description: Shortly before going out the needle of the Dregzahlmesser wobbles/jumps inappropriately to the speed. The gas acceptance is then disturbed. Almost at the same time the control light of the automatic transmission lights up as first before shortly afterwards is over. Durations about 5 – 10 seconds. This happens without medial connection to the external or engine temperature or air-feutigk He drives 50km at a time, but also stops after 5km. Once it started it often comes back soon afterwards. Without success petrol pump, petrol pump relay and ignition coil were changed. For camshaft and crankshaft sensor I have replacement, but are not yet installed. An iCarsoft diagnostic device shows an error 445 (secondary) air pump (Kat ?). This occurs again after deletion, even if the engine did not run out during the ride. If it runs – it runs great, rotates clean, fuel consumption at 11 liters What do you think you should do? Thank you Best regards Thomas