Hey guys, so I was all ready to sell our 2004 Grand Marquis (172k) and then she decided to wanted to start to misfire, I swear cars have a soul of some sort lol. I was/am getting code P0306 (misfire cyl. 6) and P0316 (Misfire detected within the first 1000 cycles). I've moved the plugs, coils, and injectors around to other cylinders and the problem did not move. Plugs have 15k on them and look fine. After running out of idea's a few days ago I decided to put in a new plug and coil boot (These have a C.O.P setup) and it didn't change anything but hey, it was super cheap lol. I've taken voltages and ohms and compared them to the cylinder 5. I've also ran compression tests and all cylinders were good, (mid 160s-mid 170s). Cyl. 6: .8ohms primary and 5.5ohms at the secondary. Voltages at the connector fluctuated from 2-2.7v, randomly would zero out or dip down to around 1v but always came back up to the 2-2.7v range Cyl. 5: 1.1ohms at primary and 5.5ohms at secondary. Voltages were between 2.1-2.3 volts. No random dips or anything. Also checked the ohms between the connector and where it connects to the main harness (under the brake master cylinder) and it was 1.2ohms, that was for cylinder 5 and 6. I have no idea why cyl. 6 would randomly zero out or dip down so low before returning. I suck at figuring out electrical problems so any help would be great. I've asked around on Crown Vic forums but they are of no help.