i cleared it (CEL) earlier today, did not return, after driving (without issue) about 20 miles or so. Yet im worried at some point it might happen again, i just feel like i didnt do anything really, but only time will tell.
I have had a CEL and code P0300 pop up a couple times in the manner the OP mentioned, the local Mazda service rep says its most likely the EGR. The EGR is still covered under warranty if the car is less than 7 years old (in Canada at least). If I pay the diagnostic fee they will scan the car, if it turns out to be the EGR they will replace it for free and they will reimburse the diagnostic fee.
Will post the results once it has been scanned.
for real? s*** i need a new free egr you taking it to kramer?
I just had this code. $1600+ later, a couple of days on the road and it's doing the same thing. Car is stumbling with no power. Car is at the dealer again, hoping they don't charge me again for the same problem.