Hi, Can anyone help? I'm concerned that there is an underlying issue with an Audi a4 1.8T that I purchased a couple months ago. After I took it home, the engine management light came on with a Cat and Lambda sensor fault. Both sensors were replaced. I have since found out that the one take off had already been replaced so that the 3rd cat baring in mind the car is 2002 plate. It has also had a new turbo prior to me buying the car. However, the Engine management light is still on and its showing a generic cat fault. Is there any issue with after market parts bringing up the warning lights? It also seems to be guzzling petrol. It's costing 17p per mile. I dont drive heavy footed and am sure that it shouldnt use that much. It has had a MOT last month which it passed no problem including emission checks. I'm afraid I don't know anything about engines apart from what I've picked up from various research and chats and would be really grateful if anyone could suggest any help otherwise I'm going to have to sell the car.....and I love it!