Originally Posted by georgew48
Coming home yesterday I started getting an intermittent blinking check engine light. It would only blink a couple of times and only when going down hill with my foot off the gas. As soon as I pushed the gas pedal back down it would go off. The engine is running fine and no loss of power. My scan tool identified it as a code p300 which Is random misfire. Like I said no rough running and no fluxiuation in the rpm and no loss of power. MPG average was just over 7 mpg. Called the ford dealer this morning and they are going to look at it. Hopefully nothing serious.
When your CEL blinks, meaning in a defined pattern, not clear then return, it means it is reading the next level up of code(s) which in turn tell the CEL to blink, is more severe than a constant ON. Do this first before you head off to the stealer, because you seem to describe constant ON, then self clearing. I'll assume you're out of warranty, if not let them fix it .Clear the code, drive it, and if the CEL returns, re-scan it to pull the code.
Random misfire might indicate one of the coil packs is failing. Whats confusing is usually a coil pack fails outright. The other thing might be a fuel injector issue (i.e. clog, failure starting). When your CEL clears by itself, the intermittent problem occuring has stopped, causing the main ECM to reset the CEL to OFF, after the sequence meets design specs.
This information you learn will help you when dealing with your stealer,is trying empty your wallet.