Well my hypertech came in handy today. I went out to my moms house 20 miles away (where I went to high school) to see my friends and one of them had his check engine light come no in his 98 1500 5.2. I happened to have my hypertech with me and plugged it in and we came out with P0307 which is as far as I know, misfire of the 7th cylinder. I've gathered: P = powertrain, 3 = ignition, 1-8 (in this case 7) = the corresponding cylinder. This is the back left one correct? (back right when looking at the truck). What are some possible causes besides bad plug and wire? It would seem weird to only have one bad plug and/or wire rather than a bunch. He has this awhile ago but it went away for some reason and now its back. He says the truck doesn't run any differently, so it seems kinda weird. Any ideas?

 

I get the code for cylinder #5.I didnt get that until my check valve in the fuel pump started acting up.Causing a longer crank time before it fires.I figure it is getting that code because of the longer crank time and reading a misfire because it isnt getting the fuel it should.Other then that my truck runs perfect.