OK, here's the deal. Today I dissconnected the O2 sensor and went for a test ride. I was really pushing the car - driving at 7 or 8.000 RPM. When I checked the exaust valve it was OK - no glowing or anything. Later this week I'm will check it again with other O2 sensor. Also there's engine light ON, but I supose that's becouse the computer is reciveing any signals from the sensor.
I'm quite sure that the problem is solved.
Ohh, yeah. About the smell. On the oil pan the sealing is leaking a bit of oil. The oil drops are directli on the exaust pipe so I can smell that stinky S
. I will change the seal.