Hey, so i just bought myself a 2002 jetta. Mildseven's old jetta to be exact! It has a unitronic chip, 3" exhaust, GT2871R turbo, eurojet fmi. Ive had it for 10 days now, and the past couple days its been acting up. When i hit it and it gets up to about 4500 rpm, it starts sputtering and missing alot. Im thinking it might be injectors or spark plugs maybe?? I need help! If its an expensive fix imjust gonna bring it back to the dealership and get my money back, so hopefully its not anything major! Thank you!