New to this forum but I just got a 2001 a4 Quattro 1.8t and three codes came up when I got it scanned. They were p0102, p0238, and p0106. Now I just replaced the air filter and the boost pressure sensor to see if that would change anything but nothing has happened. The car is very sluggish after 3000 rpms. It pulls hard up to about 3500 but then falls off and kind of coasts after that almost falls on its face. I did find an unplugged sensor behind the headlight but I have no idea where it plugs into I've looked all over that area. Some advice to point me into the right direction would be greatly appreciated. Also forgot to mention that the car is an automatic.