I work at autozone. If trained, some employees can test OBD1 cars. They stopped really training, because its too much liability. You CAN wreck an ECU testing an OBD1 car wrong depending on how you have to test it. Some cars starting about 1993 had OBDII. I've tested 94 mustangs that have had OBDII, and I've seen some 94 mustangs that havnt. Its completely random between 93-96. By 96 everything was OBDII.
