Here are the symptoms:
Rough idle... it sometime's smooths out and runs great.. but then becomes choppy again. Not very bad, but with your hand on the shifter you can feel the difference.

When driving down the road, if I take it out of gear, the idle drops bad, to something like 3 or 400rpm, then once I stop it comes back up to regular idle speed.

If I gun it off the line, it seems to be holding back until about 2000 rpm, then it takes off like a bat outa hell.

The only two things I can find wrong are the EVAP is leaking and I haven't plugged the coolant temperature sensor into the head.

I see no vacuum leaks, and I changed the TPS sensor but it did nothing to help the problem.

 

When is the last time it had a tune-up? 3 things to change. Plugs, wires, fuel filter. Also check fuel pressure.

 

Well I pulled all the plugs, and they look fine. It really feels like an ignition problem...
Sometimes, under throttle, it will "pop" and backfire... then run fine after.

 

I had a stripped battery terminal and my car was acting the same way. It also felt like it was lacking power too. It took a few miles after I fixed the battery for the idle to go back to normal and the car to feel like it used to.

 

Now you mention that last post it reminds me of when my Corvette had a battery that was about shot. It was idling really low and would even die if I didn't have my foot on the gas. Check the date on the battery; that's easy to do.