Hello, i'm new to this site. I have a 2004 deville. Check engine light is on and drawing the following codes: P0300, P0171, P0174 and P1107. Engine has a bad misfire going on now (P0300 random). The MAP sensor code just popped on as well. I've always had the Bank1 & Bank2 too lean codes for a while, but always ignored them since the car ran fine up to this point. Appreciate anyone's insight on this. Thanks.