Just like the title says it feels like my car is not pulling as hard as it once was. On top of that a friend of mine said he saw a puff of blue smoke come out of my exhaust when I took off today. I don't have any mods and have no boost gauge so I have no way of knowing if I have a boost leak. The car is a 08.5 with 18K on it. Is there anything I should be checking or do you guys thinking I should just take it in to the dealership?