Saturday i replaced my front O2 sensor because gas mileage was crap. Vag'd afterwards to verify that everything was Ok and got these codes:

16395 - Bank 1: Camshaft A (Intake): Retard set point not reached (over-advanced)
P0011 - 002 - Lower Limit Exceeded - Intermittent

17536 - Fuel Trim; Bank 1 (mult): System too lean
P1128 - 001 -Upper limit Exceeded - Intermittent

Any clues what this could be? Thanks.