I have a 2002 subaru WRX...I just had my 30000 mile service done which includes a fuel filter change, coolant, brake fluid, and a variety of other stuff. After getting my car back, I noticed it seemed to be burning oil all of a sudden. When I start my car when it's been sitting for a couple hours it smokes pretty bad, and also it isn't getting as much boost as I was before the service (according to boost gauge). What could they have possibly done to be causing this?!?! Thanks..