Jaster

Well, here goes. Normal driving in vac, no problem. As soon as I get into boost range, the car hesitates a bit and there is a little black smoke out the exhaust, from what I can see. No other mods to the car but the APR chip and FMIC. CEL came on and went away, then came on again. I recently had it checked and P1127 and P1129 are the codes - "Manufacturer controlled Fuel and Air metering". I am about to order the O2 sensors to replace them, but why will the car hesitate the way it does only at boost, blown turbos, boost leak? The car drives fine in vacuum. Happened yesterday, so I did not check hoses for oil indicating the blown turbo. Any feedback is appreciated.

What is going on and what do I need to do to fix?
2000 S4 with 93000 miles. Timing belt maintenance was done a couple months back.

B5QShip | CFDQ

when the car is trying to make boost. Pressure test asap. Likely culprit is an IC hose. How black is black and how much smoke do you see? From your description it sounds worse than just a car running rich.

Blown turbos will give you white or bluish smoke.

DAP@EPL

Second that.

ChucktownS4

sounds like you pop'd off a ic pipe/hose or check the TBB