OBD Reader / converter

[S3Graham]

I have an OBDII reader which I was given, appreciate the car is OBD I. I Bought an adaptor to go between the two. Has anyone had any luck or should I have just binned the OBDII and go

 

[bertiejaffa]

I have successfully used the converter on my cheap reader

 

[ChrisD]

I have an OBDII reader which I was given, appreciate the car is OBD I. I Bought an adaptor to go between the two. Has anyone had any luck or should I have just binned the OBDII and go

Your engine controller should be OBDII compliant ( I see that you have an M Roadster - all ‘normal’ Z3s are OBDII compliant, I’m not 100% sure on the M Roadster since the early ones had a European only spec engine). If you are diagnosing powertrain related issues then OBDII is a far superior diagnostic tool, giving industry standard ECU information and not reliant on manufacturer-specific data that may, or may not, get decoded correctly. Incorrect information is worse than none at all.
All other control modules will unfortunately fall under ‘OBDI’ which means that you are at the mercy of usually 3rd party decoders of manufacturer data that may or may not give an accurate translation. If you can use OBDII for powertrain diagnostics then that would be the way to go.
OBDII was created and legislated to resolve the issue of manufacturers doing as they pleased and not allowing diagnostic information to be made available outside of their dealer networks.