Couple a days ago I was swapping my stock ecu with a guy who had a Apr 91 ecu. My stock came out og my 1999 a4 1.8T FWD Tiptronic, while his came out of a 1998.5 a4 1.8T Quattro Manual. Both ecu's could be swapped their last three digits are 557P. We VAg'd the car and got all the codes for the Apr 91 to be adjusted to my car and once all the numbers were put in, I turned on the car and it had a below 1K RPM idle. I drove the car about a block, floored the car and it didnt feel chipped. Then once I got to the stop light it turned off on me, so i turned it back on, VAg'd the car( error code about N75 valve) which is stock. Drove the car again, same idle same troubles. Then I let the car run for about 5 minutes in park and the idling slowly went away but not completely.However when I floored the car it didnt feel like it was chipped. We dont know what the problem was, could it have been that the car needs a couple of DAYS to get used to APR 91? I dont get it!

 

Yeah... I wouldn't do that. Your ECU is specifically programmed for your car. you have 2 things going against you, the quattro/fwd and 5pd/tip. Just take it out man, it's not gonna work right.

 

are you using these #'s to reprogram your car
http://forums.audiworld.com/a4/msgs/2466542.phtml

1.8t is a 1.8t - quattro and FWD are different systems so are manual and tip as long as the softcoding is correct and the ECU should work. I've also read that it might take a few weeks for an ECU to totally adapt. somthing to keep in mind

 

or you could be having this problem cause you have the stock dv in, and it is too much preasure for it, try an aftermarket dv, see what happens

 

I do have an aftermarket DV.