I have a 2000 b5 a4 and am looking to buy a GIAC chipped ecu. If I buy the already chipped ECU from another 2000 b5 a4 would they be compatible without having to re-chip the ECU? Also, I am looking to get a downpipe. Would I have to get a chipped ecu for my car with a downpipe?

 

Yes you can use the ECU and no, a downpipe doesn't require a specific tune.

 

I just have to make sure it came off of a 2000 b5 a4 ? Does the ecu have to be from a manual as well ?

 

It needs to come from an A4 with the same engine code as yours. If you have access to Vagcom, you can recode it to work with your drivetrain (ie, change it for use in a manual Quattro, front drive auto, etc) - there's a quick recode procedure in the DIY section.

 

This is probably a dumb question , but what is an engine code ? Also , cant I just get the ecu from a fwd manual to avoid all of that bs ?

 

Yes, getting an ECU from another fwd manual makes it easier. My point was, you don't have to - another ECU can be recoded to work in your car. Engine code is stamped on the small rectangular tong on the front driver side corner of the head. Should be AWM I believe - these designators are used to differentiate between engines. Early 1.8Ts were AEB engines. I believe yours should be an AWM.

 

So the letters marked on the head is the engine code ? Im pretty sure it was AWM . So if I get an ecu from another 2000 b5 a4 fwd manual with the same engine code I can just plug it in and go ?