Camshaft Positioning Sensor Problems HELP!

[Styleprojekt]

Hey guys, quick review:
One of my G40's went out (I believe, Audi said that was it)

Heres the code:

17748 - Camshaft Position Sensor (G40) / Engine Speed Sensor (G28): Incor. Correlation
P1340 - 002 - Lower Limit Exceeded - Intermittent

Replaced the sensor, check engine light went off, code cleared, drove it for a few hours, perfect idiling no jerking when revs went lower etc

Now today, check engine light came back on, car is acting all strange again, idles badly etc

New Code is:

1 Fault Found:
17930 - Camshaft Adjustment: Bank 2: Malfunction
P1522 - 008 - Implausible Signal


Any idea if the sensor could have gone bad AGAIN? Or how can I tell if another sensor went out? Idk what to do since I have 4 sensors and I cant tell which one could have gone bad? (I was just lucky that the first one I replaced right away made the engine smooth again)

PLEASE HELP!