Another issue is that the above mentioned test is just an INDICATION. the values might actually be faulty, but because the value oscolates and stay between the mentioned above 0,1 volt and under 1,2 volt the ECU will not understand that the value is wrong...this sucks - but is just the way the system is designed.
I know some engines are really picky about wich Lambda they get. Is the one you tried an Original from VAG?
I belive the two sensors on the fly wheel (Engine speed and TDC) are either working or not. Nothing in between. If the dont work, You sholud get a fault code.
psb
