I just bought a 98 a4 quattro 1.8t.It is first audi I have owned and has front mount, bov, and manual boost controller.Car pulls 14 psi of boost at max but will occasionally cut out under full throttle and will put code in computer (manufacturer control air/fuel metering).I'm not sure where to look or even if boost controller is hooked up right.Car is also sometimes very sluggish at lower rpm's.I am lost and would really appreciate any help or advice.Thanks

Get rid of the MBC and BOV, get the computer reflashed, and install a diverter valve. If you want more boost, set it up the right way.