This may seem crazy, but how old is your battery? If over 3 years old, you might consider replacing it before spending too much time trying to track down the cylinder #1 misfire. I experienced a random stall that would only happen in colder weather when the engine was cold. Back out of the driveway, step on the brake to shift from Reverse to Drive, and the LS V6 would stall. It would start back up and run fine the rest of the day. After trying several things with not success, I replaced the battery just because the voltage wasn't as high as I thought it should be after sitting overnight. As soon as I did, the random stalling completely ceased. I suspect that starting the engine (which seemed to spin over just fine when cold) dropped the system voltage, and backing down the driveway at idle speed didn't really allow the alternator to charge it much, then stepping on the brake pedal just dropped the voltage enough to get in to the gray area/tri-state zone of the PCM. Oh, during the cold season around here, and because the car was in the garage, the headlights were also typically on for this first start of the day too.
If the battery is about 3 years old or more, you're probably not wasting money replacing it anyway, even if it doesn't fix the misfire.
-Rod
