PID = Parameter Identifier. That is what is referred to when describing sensor inputs such as TPS and MAP. They have designed one that will read the output from the map to a 2 bar scale vs the stock 1 bar scale.

Not sure how you are going to get your gauge to do that unless you can hook it up directly to a vac/boost source on the intake manifold or modify the scale used by the gauge. Propably not going to do it if it is not set up for it.