OK guys I am showngs codes P0603 and P1211. I have a bad miss and I think i can hear a hard fuel knock. The truck is running rough at an idle . I was told i need to change the RT side valvecover gasket and inside harness so I did it is no better than bfore. do yall have anyideas Or anyone live around Louisviile ky with AE equipment. I think i need a buzz test and a con. test run. Help!!