Well I tried searching around, and I hate to start a new topic on what may have been covered, but I'm looking for an ecu for a friends 2000 a4 b5 1.6, the car is located in Greece and he gave me the following:
Part number for ecu: 3Β0 907 557N
Year: 2000
Engine: 1.6 NA
Transmission: Manual
Has a security system of some kind, has abs and he's said if it didn't come standard with traction and stability control then he doesn't think he has it.
My searches based on part number turned up 3 greek websites, and not much else. Any help is greatly appreciated!

 

You'd be better off asking on audi-sport or another european forum, this place is almost solely north americans and we never even got an NA 4 cylinder here. Why do you need an ECU though? 9 times out of 10 when someone's looking for an ECU the problem is elsewhere.

 

Thanks for the tips! Will check those out, symptoms are it cuts off at stop lights and hesitates while driving sometimes and has been going on for years. I had a thought about throttle bodies being dirty and messing things up, but he says they took it to a dealer and diagnosed it there, I have more part numbers, I would think same part as a VW, don't want to mess around with the wrong parts though...
Frame Number : WAUZZZ8DZYA003198
ECU Brand: Siemens 5WP4004 02 ER SME 924417 R031 0082
Car built: 18/06/99