I have a 2002 S4 with the DP High system upgrade, including airbox lid mod and ECU. After a recent service the shop reinstalled the stock ECU as the bike runs better at low revs with the stock ECU. It might run better at low revs but it doesn't spend much time at low rev's. As I have both ECU's and airbox lids I am interested to run some comparisons and change over the ECU. Is there anything more complicated that just replacing the ECU's and connections??