what would cause my truck to idle at higher rpm's?

Check all your vacuum lines when the engine backfired it most likely blew one off.

sounds like a vacuum leak. If that has a plastic intake i would start checking for cracks and i would check all the vacuum lines that go to it. Check the intake tube for cracks and just anywhere air can get in after the MAF sensor. I would check that too just to be safe. A backfire in a new"ish" car of truck with fuel injection can be very bad on the intake parts. It isnt like a backfire out of a carb and intake where it can just blow the flame out of the carb.

it's not new, it's a '96

It is still fuel injection though. It cant handle backfires like a carb can.

You should look into why it backfired in the first place. Is the the 3.4L V6 or the 2.7L 4 cyl? Really either engine should not be backfiring unless it has something seriously wrong with it. On the 3.4L and some 2.7L engines, the timing and fuel are controlled by the computer, so there is a much lower chance of backfire under normal conditions. While your Tacoma is not "new", it has a modern engine in it. From a mechanical standpoint there are few differences between your engine and the 4.0L under a 2012 Tacoma. Is your check engine light on? I wonder if you have a faulty sensor.

i think it was a hiccup with the sensor because i looked for leaks and found none and my truck is no longer idling at high rpm.