Hello, I picked up the Omega from a timing belt change again and wanted to drive home. After about 5 minutes driving I noticed at a red traffic light that the car vibrated. I first thought about the automatic, however the problem remained also when I switched to “N”, so rather not the automatic or? The engine fluctuates between 450-600 revolutions. At the next traffic light again the same game, in addition the exhaust gas control lights started to flash. Then I returned to the workshop, error code was read out and the result was: – 0420 catalyst efficiency under limit – 0300 Several cylinders misigned – 0302 cylinder 2 misigned detected – 0306 cylinder 6 misigned Then the spark plugs were switched from the cylinders 2 & 6. When I then picked up the car again at the first best crossing then exactly the same as before. Since someone has an idea what this could be? What also irritates me, that if you e.g. from the stand – in which he still vibrates – it could be quite cleanly accelerated.