Due to a spark faillure, engine was changed in Aug-2002 with 45.000 Kms. As result Max Power decreased to 161 HP and loss of torque/power in all range. Figthing with AUDI SPAIN for 17 months new engine (number 3), butterfly, exhaust syst, cataliz, mass measure, turbo, main electronic device and other things have been changed.... but although 184HP have appeared at 6.000rpm, from 2.500 to 5.500 rpm I´ve lost 15-25 HP.... I´m desperate, nobody seems to know where is the problem and AUDI is making the effort. ¿Any idea? Regards.