OBD not ready

hey, i took my car to get inspected and it failed because a lot of things were not ready, now my mecanic said drive the car which i did for two days, yesterday he said take it again and it failed again, so now i have lost more money, it seems like it doesnt want to get ready. what can i do? can my radio be causing this? i read somewhere that if you change radios you might get problems with reading the OBD but the thing is the computer comunicates with the car and reads its stats only thing is that it says its not ready. help would be greatly appreciated.

these Monitors apear to be not ready.

Catalyst
Evaporative System
Secondary Air System
Oxygen Sensor
Oxygen Heater

so far i have changed 2 oxygen sensors and still no luck. What driving procedures should i do.

i read one from a data cd about my car it said, on a cold start drive for 75 Miles going no faster then 56 Mph, can this be it? thank you guys.....

I had the same problem. I have a 1996 Passat GLX VR6 and it has failes twice. Then I drove for a about 1000 miles and everything was ready. I drove mostly on the highway. Just keep driving it and do not disconnect the battery.

I found my problem, i have an Alldata program.

the thing to do is drive the car for 7.5 miles at now more then 56 miles per hour on a cold start. that will to the trick.