Scan Gauge as diagnostic tool
I tried an experiment yesterday with my scan gauge 2. I disconnected the intake air temp sensor and MAP sensor, to see how accurate the scan gauge would be at retrieving codes. I got P0108 for the MAP sensor (high voltage) and P01113 (High Voltage) for the IAT sensor. The Scan Gauge easily cleared these codes when I turned off the engine and reconnected the sensors. It couldn't clear the codes with the sensors connected and the engine running (probably normal). Had this been a real situation, I would have known where to look. Also I would have saved a trip to the dealer (van still under warranty) or mechanic ($50). In a real world situation I would have avoided being taken by a sneaky mechanic. This may be a way to find a trustworthy mechanic. Disconnect a sensor, then reconnect it, not enough to make contact, get the check engine light to come on, retrieve the code, remove the scan gauge, take the vehicle to the mechanic, and see what he/she has to say. If he/she gives you a diagnostic that is way off/expensive, then you pay the fee and go to the next. This can be an expensive experiment, but I believe it will save you money in the end. Just my 2 cents and another reason to take the plunge and buy a scan gauge 2.