E46 320i problem

Hi, today I drove about 20 minutes and the car went fine, then I stopped at friend house for 15 minutes, I went back home but the car didn't go as well as before 35 minutes ago. I drove about 30km/h and I ranked second gear and when I stepped on throttle pedal, the engine choked at low speed. That's the same thing when I start and I rank first gear, it doing the same. However it's happen only sometimes, because the car drives once normally and once not.



Thanks for advice.