Thanks for the link and the advice TB. It appears P1316 means "misfire excessive emissions fault". I'll check the plugs and wires to see if that's the problem but I am a little doubtful cause I have replaced them with new ones. I did notice some 'rough idling' or 'missing' when I started it up the other day. My truck has a relatively new V8 so I am a little concerned as to why it could be missing, showing a misfire code, etc. Thanks again.