Without the CAT numbers visible, a smog technician has no way of verifying whether or not the catalytic converter was designed to be used on your vehicle. As such, the vehicle can not pass a smog check.
Since the implementation of the STAR smog check program, smog stations are being very careful in ensuring vehicles are equipped with proper/required catalytic converters. The smog check technician will check your vehicle's catalytic converter EO numbers. The EO number must be visible. If the CAT is missing its numbers or the numbers can not be located, the vehicle will fail the "visual" portion of the smog inspection. The technician must be able to see/read the EO number in order to determine the CAT is designed for use on your vehicle. Perhaps using a small mirror will help the situation?
posted by SmogTips Support