OXYGEN SENSORS

[Pfs600]

Hi

I am hoping that someone can shed some light on this for me, had MIL light come on VAG-COM said B2S2 sensor open circuit and resistance to high, i have replaced this 3 times now and the reading always comes back, i now have B1S1 as a fault as well and the car runs like a bag of nails, but only sometimes, it will run like <beep> then all of a sudden run fine even with MIL light on, then it might not idle very well, but then it may correct itself, now the driver exhaust is sooting up and sometimes blowing out black smoke, here are the readings, hope someone can help

8 Faults Found: 16518 - Oxygen (Lambda) Sensor B1 S1
P0134 - 004 - No Activity - Intermittent - MIL ON 17536 - Fuel Trim; Bank 1 (Mult)
P1128 - 001 - System too Lean - Intermittent 17530 - Oxygen (Lambda) Sensor Heating; B2 S2
P1122 - 004 - Open Circuit - MIL ON 17548 - Oxygen (Lambda) Sensor; B2 S2
P1140 - 008 - Internal Resistance too High - MIL ON 16684 - Random/Multiple Cylinder Misfire Detected
P0300 - 002 - - Intermittent 16685 - Cylinder 1
P0301 - 002 - Misfire Detected - Intermittent 16687 - Cylinder 3
P0303 - 002 - Misfire Detected - Intermittent 16686 - Cylinder 2
P0302 - 002 - Misfire Detected - Intermittent Readiness: 0010 1001