Dedra gasoline consumption power loss

Hello, I have to get annoyed again…. Would you like to ask what it can be, that the car has a slightly higher fuel consumption and also a power loss in the warm condition. The engine runs quietly, speed if cold at about 1100 and after a few minutes it goes down to about 800. Acceleration if cold, is ok. Has however still a slight jerk or buck if the car is cold. Have tested all plug connections and treated with contact spray. I cleaned, were only slightly black worn. Then after 150km and after the cable testing action, zünkerzen a light deer brown. Candles are not oiled. Nevertheless new pure and now it is smelling really smoother *Beru ultraX* To the problem, when the engine is warm, it does not go through so well and I think also consume a little more fuel than usual. Power loss but somehow only in warm condition. Engine temperature if warm to approx. 90°C-94°C. If cold, also the one Küh Cold medium hose, the other one gets warm. Thermostat ok?! Have brake cleaners standing here and want to clean the throttle flap with LMM, do I have to take care of something? Detections is clear…and not in the built-in condition. Can I also be the Lambda probe, can I check it myself? Would be nice if someone could help me again. Thank you, Alex