I had earlier posted my concern that sometimes, I would start the car and the idle would go to 1200 RPM where it should be, but immediately drop to 200-300 and sometimes die completely. My only fix was to add slight pressure to the gas pedal for those first few seconds of starting.
I researched some threads, read everything I could, and finally decided to try something. My thought was that if a sensor was not properly grounded, it may send bad info to the ECU and that could affect fuel mixture, etc. Result: the following procedure gave me 150 miles to a quarter tank. Previous to this mod, mileage was 125 at 1/4 (both under highway driving at speeds upwards of 65 MPH). Mileage increase may or may not be related to this mod, but I enjoy it, nevertheless!

I took out my stock intake, removed the ground from my battery and looked at where it was grounded, just under the part of the intake that is bolted to the car (which I removed). The ground went from there to the engine block. I wanted to add a ground (as short as possible, but directly to the chassis), so I disconnected the battery ground cable from the chassis (the part just under the intake bolted to the car) and scraped off paint to bare metal. I took a washer an inch in diameter, wrapped 18 gauge speaker wire around it, then bolted the battery cable down on top of the washer (which was in direct contact with the bared metal on the chassis). I re-installed the intake and ran the new ground wire under the scoop and up to the MAF sensor. I cut a segment of insulation off around the wire (not actually cutting the wire itself) and wrapped the new ground around the existing black wire ground. After taping it up with electrical tape, I started the car and have not since seen shaky idle. The idle jumps to exactly where it should be at start-up.
NOTE: My throttle body was cleaned for a second time up to butterfly plate. This "mod" is not necessarily the fix for your symptoms, but it may help.

 

I'm more inclined to think that this fixed your idle issue. You should open that butterfly plate and clean further in.

 

I would have agreed, but I cleaned the TB about a month ago, and the first start of the car after cleaning (literally minutes after cleaning), the car almost died--just like it was doing before. I gave it a month before I cleaned it again. I removed very little debris this time, but the first start after adding the ground and since then, the car has hit perfect idle at start up.
Also, I would like to clean past the butterfly plate, but I am reluctant to just start removing bolts. Anyone else done this BESIDES just spraying some TB cleaner into the open intake w/ engine running?