pass problems that i think can relate to this, the dv holes was completly off from the intercooler hose, header that connects to the exhaust cat was lose, i found little amount of oil in the intake.

Just bought a audi a4 1.8t and problem started. when i bought it the DV to the intercooler hose was completly off and oil was in and around that area. i had all the minor defeat fixed. at first when i turn car on i see white smoke just at start but goes away after a 3-4second idle. after that, when i gun it like 4k-5krmp i see black smoke (alot) what i think is a head gasket but what i know is that oil burn is not black but blue. my second guess is running rich. i had it scan and the codes dont seem to lean at that direction. car runs and performance fine running at 18-20psi. here is the information on my car, suggestion would be great.
vag scan:
p0102 -MAF or VAF A circuit Low input
p0140-O2 Sensor Circ.,Bank1-Sensor2 No Activity Detected
engine mods:
-front intercooler
-giac chip
-DV
-intake
-2.5" down straight pip no cat