Had a bad misfire, so I took off the valve cover... cover... and checked the connections for the coil packs. ISTA was telling me it was cylinder 2. Sure enough, the connector was slightly loose, so I swapped the coil pack with cylinder 1 (just to be sure) and re-checked all of the connections for the ignition coils. Seems OK now, but time will tell. It did it intermittently for the past 2 weeks up till today.