during the last couple of weeks my normally mild winters, southern home has gotten to single digit temperatures range at night. On several of those super chilly mornings the checking engine light has popped up with P0304 (misfire on cylinder #4) and P0316 (misfire during 1st 1000 revolutions) on my 2012 XLT 5.0. Clear code and all good the rest of the day (temp rising into the balmy 30s). My first thought was the OEM coil with 213k failed so a new one was installed. But the codes return on some mornings, though not every morning.

this part is just a rant, why does the remote start up quit working when a code is set? Clear codes, remote start works.

 

How many miles on the spark plugs?

 

changed them at 120k

 

213k now? They are due.

 

Seems like if the #4 plug was bad, it would be bad all the time. I don't understand how the cold factors into it.