Mini Cooper R50 EZ02/2004 Errors P0302 and P2270

Hello together, I’m new here and hope someone can help me. The following problem, I got a used Mini Cooper R50, EZ 02/2004 on the weekend. Since yesterday unfortunately the problem, which starts already after a short time the ASC light and a short moment later the engine control light. To this end, it throttles down immediately and I can hardly accelerate. In addition, it jerks during the ride, like a tractor or so. Also the idle run is very restless. I know this error probably also existed before the purchase. Therefore, the spark plugs, the ignition cables and the ignition coil were renewed. It probably went a few days well but now again the same error. I had it read out yesterday directly in a workshop. It only meant that this error is frequent and often the cause difficult to find. In the worst case the head seal should be broken. I was then in another workshop and the thought of head seal it can not be, then there are other error messages. I should have other candles and a different ignition coil build up. In the worst case, I don’t know very much about it and I don’t have a lot of trouble.