Guys I need some help. I have a 2008 avalanche LT with close to 120,000 miles on it. i have just notice after starting my truck there is a white grayish smoke coming from the exhaust pipes. The smoke is very noticeable but isn't a lot that you can't see or anything like that. It will smoke for about 3 minutes and then about 30 seconds after driving it. The check engine light isn't on and I haven't notice any problems in performance wise. I don't think it's water or condensation because it does it when it's about 60 degrees outside. I just recently changed the oil pressure sensor, you think it could be something with that. Checked all the fluids level, they where fine. Oil might of been a quart low. Just changed the oil and put 10W30 in it instead of the 5W30 that I have been using. Any my idea what could be causing it to just start smoking like that at start up, it's not effecting performance. It's just embarrassing when I start the truck up? help please!!