Engine stalls

Bought this car used and keys were worn out bad, turns only if lucky. Bought new ignition cylinder with key and car started and idled, all seemed fine for about two days. Then would only start and idle for about one or two seconds then cut off. I had replaced oil pressure sensors (both), coolant temperature sensor, plugs, ignition wires, because it had done this before. Also the idle seemed unusually high before I replaced these. I hope I didn't leave anything out, this is my third CITI Golf, and I have never been so dumbfounded by any Golf issue. Also seems my intake pressure sensor is faulty.