Hi Omega friends, unfortunately did not pass the exhaust gas examination – can someone advise me how I can help myself here or fix the problem at the favorable? Omega Karavan, 2 liters 16 V, 136 hp (100KW) 1994 Bj. Otherwise the car runs perfectly and consumes almost no oil. What causes bad exhaust gas values? Can I replace some components for this (such as the Lambda probe or similar?) Would be very grateful for every whiteness. Greeting, Mike