I have a 2003 EB with 160k miles. I have done a good amount of work to it and have kept it well maintained. Installed new radiator, fuel pump, fuel filter, battery, alternator, starter, spark plugs, coils, have been changing out the oil and filter every 5k miles with royal purple 5w-30. Did some mods to it k&n intake, air raid spacer, bbk throttle body, muffler delete. She runs good and strong. I noticed a few weeks ago I got a check engine saying that the engine is running cooler than usual the temp was at 160. I knew it had to be the thermostat but I kept running it for about 2 more weeks until I had the time to replace it. I got a new thermostat and housing started her up and got good temp at 190-200 which is perfect then on a few trips I got a check engine light for misfire on cylinder #1 I checked the spark plug and replaced it but the code stayed on after clearing it and kept misfiring. I thought I might have gotten some water in there when replacing the thermostat I kept driving it like that and one night after work I started it up cold start on a cold day and noticed white smoke from exhaust I immediately got worried went home checked the oil and it looked good. Did an oil change and ran it a few more days. The oil looks great no coolant mixed in it, looks brand new after a week. Another cold start in the morning on a cold day about 3 days after the 1st time and got more white smoke from exhaust. My guess is that it was moisture since its been cold. Been checking the oil, coolant, etc everyday and everything looks fine. The misfire went away, no more misfire or check engine light. I took out the new spark plug to check if there was any coolant on it and I did see some dry dirty coolant water on it. Has anyone ever had this issue? I've been driving it daily, freeway and city, 3 days now and no misfire, no white smoke, or anything. Has never overheated, temp stays at 190-200. Could it be a bad intake manifold gasket or do you think it could be a very small head gasket leak that only opens under high RPMS? I don't know what else it could be. Sorry of some of this doesn't make any sense wrote it up super quick as I'm at work. Feel free to ask any questions or give me any info. Thanks