Hi Guys Just be your opions please if I can. I have just driven my car without the oxygen sensor connected. The car seems to run exactly the same. Do you think this could affect fuel/ratio's ? I'm fairly sure if must be F**ked. Will get a voltage meter and try and check it. I have run a test on the ECU and it gives me codes 21/31/34 21= Ignition system fault ( crank angel sensor reads 120 point from the ignition coil? ) 31= Neutral/Air con 34= Knock sensor ( I have a question? Does the standard knock sensor retard timing? Or if I fix it will it then start retarding timing? Would appreciate peoples opions Cheers

If you had a CAS Failure, your car woudlnt start at all. an HT lead being disconected can cause a code 21 .. also make sure to clear the codes before starting, it might just have logged an old code. Code 31 is System pass for non aircon'd car, or aircon fail if you have it present. Did you turn the unit on, then off when running the tests? This is needed to cleart that particular code. Knock sensor code i *THINK* (dont own a turbo) means its detected knocking at some point, and yes, probably backed off the timing.. It might mean there is a fault with the sensor and hence there would be no protection... As I said, try clearing the codes first, then running the test procedure again.