As with most turbocharged cars, I'm sure an ECU upgrade would enhance performance with the 996TT. However, with my current Audi TT 225 Quattro Coupe an ECU upgrade caused a failure of the diverter valve. Without the increase in power Audi TTs still had failing DVs (made by bosch). Currently I have the MTM Stage I ECU upgrade with a bailey DV and it has been working fine.

Does anyone know someone who has upgraded their ECU or done it themselves? Has the performance upgrade been noticeable, and has it shown on the dyno? Has anyone had a problem with associated engine components after an ECU upgrade? And, finally, how easy is it to swap the ECU in and out?

Sorry for all the questions, just looking for some info.

 

Doc-

The Bosch manufactured DV in the 996 TT is a known problem and many owners have chosen to replace this with a Bailey DV (some have used Forge). Some have waited for the characteristic "honking" sound suggesting failure but many have switched out prophylactically. There are several ECU upgrades available which provide very noticeable seat-of-pants and dyno proven improvements. There is no shortage of ECU "upgrades" which will lead to any number of engine problems, both actual and fault-code indicated but also no shortage of very fine ECU tuning options (RS, FVD, Evo/GIAC, APR etc etc . The ECU is quite easy to remove.