Mitsubishi Repair: 1997 mitsubishi gst 2.0 turbo auto, head gasket, performance tune

Question
i bought the car with the engine light on and took it in for a high performance tune up that costs a pretty penny but after 2 days the engine light came back on and i didn't notice a difference in the ride. The problem is that when i start the engine i get some block smoke and oil seems to shoot out of the exhaust and i am slowly leaking oil. it runs fine at lower speeds but once i get up to 60mph the engine seems to shoot out black smoke and alot of smoke when i go up hills. It also shifts very rough and sometimes doesn't shift until i brake then accerate again.

Answer
Scott: Why did you not get this check engine light checked before you bought the car? Tune up, high performance or not most likely will not fix that check engine light. As the computer in your car is finding a problem in the system and so kicks on the light. So you need to have your car coded, that will check the computer and all its sensors. If you are loosing oil out of the exhaust that does not sound good to me,  as you could have a weak or bad head gasket. You need to get this checked out before you mess up the engine more. Why when you had that high performance tune up did you not have them check the engine light and the oil coming out of the exhaust? Does your car heat? In so use water, could there be water in the oil? Another reason for loosing oil and having that oil blow by; is the rings are bad and so the oil is getting past the pistons and so out the exhaust. So you see why you need to get this car checked out in an shop? Shifting could be from the engine not running right or it might be a problem with your transmission or clutch. I think I would have the car engine checked out and then go from there. I hope this helps and good luck! Linda