Ok, I was just going back through all of my old posts, and found this...Figured I ought to update everyone on the situation.
Over Christmas break, I brought my truck into the shop to have it checked out because it was going to fail emissions, and I needed to renew my registration. Anyhow....here goes.
After a week in the shop, it was determined that I had several problems.
The Bank 2, Sensor 2 O2 sensor was faulty - replaced.
The Throttle Position Sensor had a bad connection in it at 5% throttle, which was causing the IACV-AAC valve and the EVAP Vent Valve to flutter, causing my stalling problem. Replaced the TPS.
The truck had been in the body shop since my idle issues began and apparently the body shop had attempted to adjust the idle using the adjustment screws on the TB and totally FUBAR'd it. Replaced the Throttle Body.
The IACV-AAC Valve was experiencing intermittent shorts, so it too was replaced.
After replacing the EVAP Canister, lines, and valves twice each, the EVAP codes still existed in the system. After replacing the TPS, the EVAP codes went away.
So, if you're experiencing an EVAP code, the problem may be something not-so-obvious.
All of this, including the long hours of diagnostic labor, cost me about $2200.
However, the truck is running better than ever, and on the way back from VA to NY (non-winter blend gasoline), I recorded 18.4mpg on the highway!! Beating my previous mileage account of the same trip by nearly 4mpg!