Have a Skoda Octavia Petrol 1.6L 01, from a cold start, so say I have left the car sitting for 8 hours or more start the engine and there is loud noise from under the car, sounds like a diesel, and sounds like the exhaust but there is nothing wrong here. Lack of power from the car for about 30 – 45 seconds, car easily cuts out. Noise continues until it warms up a bit goes away after a few minutes. Then all is fine. Anybody any ideas?