So as a background, about a year ago I had an issue with these codes along with running very poor. It felt like a misfire/studder/running on one less cylinder) and when puling in the driveway it stopped after 2 minutes. Then she drove perfectly fine. Happened again about a month ago (out of state) for about the same timeframe. Although this time added a code P00C6 (and never appeared again) to the mix. Again after a couple minutes it ran beautifully. I even tried a different tune to see if things would change at this point. Then today it happened again while driving and smoothed out shortly. I know I have read a few members with the same issue but never heard anyone diagnose the actual issue. Just seems to go away and forgot about.
To add, the first two times had P0304. When that happened I swapped out the coils but swear I changed #4 & 6 coils to see if it would change. Could be wrong though as I have slept since then. What confuses me is I swore it was the #4 injector (and was about to change it) since i assumed it was sticking open but now i'm looking at the coils?
So my questions are:
1) Will a coil stop working, then be fine for a year and stop again? Intermittently?
2) Will an injector stick, work great and stick again as above? Or will it stay stuck open?
3) Am I missing an underlying issue like a stuck waste-gate or a turbo having a bad day?
I have no issue changing whats needed but after the money I have spent on this ride... I would like to not go buy parts assuming I know what it is and be chasing a mystery. Would love to hear what others have done when having this issue with their babies.
Recent changes to the car in the last two months, New Motorcraft sp534's gapped to .029-.030, fluid change in PTU, fluid flushed in trans, engine oil changed (did not see any fuel or water in oil when changed or catch can). All other mods to the car are below. Thanks in advance! Still at about 50k miles.
