2004 throwing codes after tune-up
I have a 2004 Mustang with the 3.9 engine. It had been idling rough and having lots of hesitation under load. The CEL flashed and I got a P0303 code. I replaced the coil pack (used Motorcraft brand), the plugs (NGK) and the plug wires (whatever the brand Autozone had in stock). Everything has been fine for a couple of weeks until today, the car started running rougher than ever, had major hesitation when accelerating. I got home and pulled codes P0300, P0303, and P0316. I am pulling my hair out, any idea what is going on? Any and all help would be greatly appreciated.