Hello all new to site as well as a recent cobalt owner obviously I have questions. Here goes ill keep it short as possible. 2005 cobalt ss sc 112xxx miles seller said it has 2.8 pulley 60lb injectors and asp tune. Stock appearing intake stock exhaust. One of my two questions is....how much boost should I be hitting it hits a wall at 15psi. Redlines at 6500. 2 I get a injectors running to rich vel every now and again? And help or direction would be appreciated!