Not sure on the V6, but my drive by wire throttle was replaced under warranty for a similar intermittent problem on my V8. On mine, the throttle would respond with too much throttle when starting from a stop and when you backed off the engine would die. It was very frustrating as it would only die intermittently and left no fault codes for over two years. When it finally left a code, the code did not really give a direct clue. Fortunately for me the mechanic at my dealer had read or heard that the problem was related to the throttle body.
+1 on that. Even getting the dealer to flash a later factory tune will make a big difference. I use Torrie's tunes on my 04 LSE, but over the past four years, I did have a newer factory tune flashed to my car and it made a huge difference. Almost as must as the custom tunes made when compared to the old stock tunes. BTW the drawback to having a new factory flash is that all you custom tunes have to be redone.
Depends entirely on you dealer. Also on your warranty status, Under warranty it is free. My dealer always checked for newer flashes when ever my car was in for service. In most cases the new flash addressed things that did not impact my car so we did not use them. Sometime in 2005 IIRC, a new flash became available that addressed enough issues the we decided to use it. It addressed transmission issues along with a list of driveability issues that upgraded the UNG0 coded program that came on my 04 LSE.
