I have had probably the worst luck with my S40 1.9T, and by looking at the posts on here, some of you guys have too. My car died about 2 months ago...and it ended up the turbocharger was overboosting and needed to be replaced. So I got that fixed ($1600). I have gotten new spark plugs, a new boost sensor, and a few other things fixed. Yesterday the check engine light came on again with error code p0130. Would this just mean I might need a new o2 sensor? How much of a difference does regular vs. premium gas make?