My 2000 audi a4 quattro wont connect to emissions cpu?

I have a 2000 Audi a4 quattro. Recently i have had to do a lot of work to this car. I had to do stuff with the cylinders and also put a new transmission in it. I went to get it inspected after all of this work and it passed, until they tried connecting it to the emissions computer and it would not connect to it. If anyone knows more about this or has any information on this topic at all it would be very helpful. Thanks all.My 2000 audi a4 quattro wont connect to emissions cpu?Hate to say it but somewhere during all your repair work you must have done something wrong and with the extend of work you described it could be anything. I would go back to the drawing board if I were you.