CEL, VSA light - continued. - AutoZone's reader indicated an engine misfire, cylinders 3 and 6 and suggested several things, including: Vacuum leak, ignition problem, bad gas, engine problem. The engine drove perfectly to AutoZone. The VSA and Triangle did not come back on for the trip, but the CEL stayed displayed. Car drove fine back home. I then removed the ECM fuse (fuse box under hood) for several minutes to reset the CEL and any stored codes. Have drove about 25 miles since. No CEL light so far. Car running perfectly. I THINK the problem was related to "over filling" the gas tank and letting it sit in a warm garage (daytime temp 85 degrees). My point is not ALL P0306 codes are such a big deal. Reset by removing the fuse and see if it comes back before taking it in for an expensive visit to the dealer.