Those scan tools are ok. They will: 1. read, and erase, the DTC (Diagnostic Trouble Code); 2. indicate how many “monitors have been set” (how many of the monitoring systems the computer has tested and decided that they are monitoring ok, or not monitoring ok); 3. display Freeze Frame data, for the moment the primary DTC code came on (such as: engine temp, rpm, engine load, car’s speed, fuel trim). That’s it.
To see what the sensors, and actuators, are doing, you need to go to a scan tool with a screen display (its own display screen, or uses your personal computer (pc)). These start at $250.
Go to: www.autotap.com for some articles on using scan tool data. They have a symptom and cause booklet.