[troyjan]

Easy problem to identify.

Im going to say it's the Vacuum Senor which is
Mazda's version of a MAP sensor ~ (manifold absolute pressure)

You can easily test and verify by simply removing the vacuum hose and wire's from the switch witch is located on the passenger side fender near the fire wall. It is labeled Vaccum Sensor.

Once you have disconnected the switch restart your truck and see if you notice any difference in performance. Reconnect and connect while motor idles.

Now, If you could please help me with something it would be appreciated.