how do i know what ecu's are compatible like for swapping from car to car and different chips

 

All ECUs have aPart Number on them. Those numbers should be the same or at least similar and come from the same year cars with the same engine code, transmissions, ESP options, etc... you need to know all those things for sure if the p/n's are not identical. The ECU that I use for my 2000 A4 came out ofa 2000 Passat with similar options, and although the p/n wasn't the same, it still worked fine.

 

Bogie,
In your sig it says you have a sport tuned ECU. So, my question is, did you get the ECU already tuned, or do you have another addon like a juicebox or something to make it "sport tuned"? Do they sell ECUs that are compatable for the A4 that are already tuned up?... Sorry about all the questions. I am totally new to haveing a car that I might want to upgrade the computer so I know nothing about this really.

 

for your car pretty much any aeb/dbc ecu will work
you have the 557p

if it dosent initially work it will need to be vag recoded to work properly

 

I have no idea what aeb/dbc means or 557 for that matter.

And what is a vag recoding anyway?

I did say I was totally new to this right?[&o] lol

ty

 

i was talking to the original poster

you, need to go read the faq