Hi, I know it's probably not this, but does the problem go away after a few minutes of driving? Mine did that forever, and I could never figure out what was causing the problem. And it became much worse when the weather here got cooler.

Problem: low-octane gas. We'd ben using the cheap stuff since day one. Then one day, I tanked up with the good stuff right before a road trip. I guess it cleaned the engine out, and got it used to running high octane again. i have never had the symptom since (never used the cheap stuff again, either). My guess is that the knock sensor was probably going apeshit with the cheap gas, and that's why it was running so bad.