There are a number of easy scan tool tests. One is to compare the manifold air temperature sensor with the coolant temperature sensor. When the car has been sitting over night, they should read within a few degrees of each other and be similar to the ambient temperature.
Compare the MAP and barometric pressure sensors. They should be very close to the same value when the engine is off. When then engine is on, the difference should be about what you read on your vacuum tester.
Make sure the thermostat is working right. The stock thermostat is 195 degrees. Running the engine run too cold can cause idle problems. (Of course, if you have a Hypertech chip like me, you WANT it to run colder... 160 degrees with the aftermarket chip I have.)
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