Ask an automotive repair technician who works on domestic cars what he thinks of OBD II, and you may be surprised with the answer you’ll get. Many of these techs will tell you that OBD II gives them far less information than they were already receiving on their scan tools through the conventional diagnostic connectors that have been common on domestic cars for many years. To them, OBD II-with its government-mandated data requirements, seems like a step backward.