Count me among the many converts who have gotten a huge power (and grin) boost with an ECU program change. I must confess that lately my head had been turned by my other favorite ride, the BMW E39 540i 6-spd. After thoughtful consideration to the thousands of dollars already spent keeping my 2001 A6 2.7t 6-spd. in good shape, I decided to try and meet the 540 head-on in the one category it clearly was superior in ; acceleration. So for a few hundred dollars more, I now have a 540i killer. The car is now scary fast and yet, it returns as good mpg (maybe better) than before if I drive it 'normally' (hard to do though!).
The only gremlin is that I can't 'floor it' until I coax the throttle through 3,500 rpm. Mind you, the first third of throttle travel is all I need now anyway for the thing to rocket along more quickly than it ever did before, so 'coaxing' is perhaps a mis-leading word. If I mash it from say, 2,500 rpm though, it bogs down and cuts out when it hits 3,500. If I feed throttle to 'keep it right on that edge' until 3,500 rpm it behaves as though it was floored, and once past that point I can floor it and hang on. Having learned this 'trick' I love it! I still think the 540i has a better balance of ride comfort and handling but I no longer pine away for extra horses, and that includes looking at 4.2 Audi's either.
Has anyone else with an APR chip experienced the need to 'manage/coax' throttle feed to maximize power delivery? BTW, I did have to replace the 'Y' intake tube which I discovered had a crack, and changed the plugs, but they still didn't cure this (non) problem.