Hey I'm new to these forums and I have a question. I just bought a 2003 WRX from a dealer and when I test drove it it was fine. Turbo was kicking in good everything was smooth. Brought the car home last night and when in 2nd gear I start accelerating for turbo to kick in the car shakes as if it is going to stall and in 3rd gear does the same but a loud BANG follows. The bang is almost like a rock hitting the hood of the car but 20x louder scary s@#! The guy at the dealer is an idiot first off I don't think he used 91oct gas and I know he definately didn't put synthetic oil in the car when he did the oil change. I know this for a fact because I found the company receipt for the oil change inside the car. Could this be causing the car to be acting weird?? Anyways I'm going to the dealer again but I was wondering could this be reparable and what can it be??? Anyone with some info that can help me I appreciate it. Thanks.