Buly,

Are you using 100LL?  Leaded fuel will kill O2 sensors quickly.

If you are running leaded fuel save yourself some wrenching time by changing
the O2 sensor first.

Jeff Owen

>During the flight I noticed my mixture bar was going from lean to  
>totally desapearing. Turning the knob to full rich was not enough. So  
>I have to do some more tuning.
>Bulent "Buly" Aliev
>FXE Ft lauderdale, FL