Help my omega makes bitches!!! He’s jerking and oil is getting more and more

Hello together. I’m relatively new here and I’ve been looking for answers for days, but unfortunately I haven’t come to a real result yet. I used the SUFU but either there’s no problem, I entered the wrong search term, or I’m just too stupid 😉 My problem: I’ve been driving an Opel Omega 2.5 V6 Bj 04.95 for some time now I’ve noticed that it’s just speeding up (by overtaking) in the upper speed range somehow the Leis It can be felt a little jerking. If I then reduce the gas and slowly give gas again it is usually gone (the jerking) either. There are no control lamps on or something like that. I once had the error code read out but only the FC 31, but that’s how I could read here quite normal. There are posts with similar sympthomes where it is described that you should place the AGR still or clean the throttle flap etc. but I’m not sure. I checked spark plugs and cables. Everything was fine. I checked my oil level about 2 months ago and found that this was about 5mm above the min stroke, so I filled up oil until the stand was just before max. Yesterday I checked the oil level again and had to find out that the stand at once is above max about 6-7 mm. The level of the cooler water is unchanged and also the smell of the oil does not smell like Benzi. n. It would be really great if someone could help me what it is and maybe give a small instruction on how to fix the error. Thank you in advance LG Andy