This afternoon I noticed the car didn't run good in higher gears and I saw A/F dropped to 10 ,normal it is around 11.5 at full throttle,but got no cell's,tonight I wanted to test again and the car drove very good again but suddenly I heard a big rattle coming from the engine and the check light flashed and got a message: DRIVE ENGINE RUN TO WORKSHOP.
Oil pressure is fine,A/F is fine and even boost is normal,but at low rpm and at idle car is making a noise like on old volkswagen beetle and shakes a little bit,seems like he is running on 5 cylinders.I have the brockway r920 and it shows no DTC errors.I hear no rattling noise anymore but the car makes a very strange exhaust sound and shakes a bit.Anybody got an idea what the problem could be?

 

Have it towed to your shop. Don't drive it. You mentioned you had a strange exhaust sound. If you are lucky it is indeed an exhaust issue which can be fixed very easily. A bad cat or baffle in the exhaust could cause these symptons but I tend to think it's something more serious. Keep us posted and good luck.

 

If you have a check engine light, then you have an OBDII fault code. Have it read, but I agree with LA Tech, don't drive it and get it towed to a shop.