2013 Ford F-150 Misfire Under Load - P0300 and P0306

Question

My 2013 EcoBoost has developed a nasty shudder when I'm merging onto the highway or trying to pass. It feels like a quick stumble, almost like the transmission is slipping, but it's definitely an engine misfire because the CEL starts flashing.

I pulled the codes and got a random misfire and a cylinder 6 specific code. It only happens when I'm heavy on the throttle in 6th gear at lower RPMs. If I downshift, it clears up.

BMW_Bjorn · Accepted Answer

✅ Confirmed fix: Found that the spark plug boots were tracking. Even though you replaced the plugs, the carbon tracking on the outside of the porcelain on cylinder 6 was causing the spark to jump to the head under high cylinder pressure. Replaced all 6 ignition coils with factory units and the shudder is completely gone.

InternationalIan · Answer

This is a classic condensation issue in the CAC (Charge Air Cooler). When you cruise at a steady speed, moisture builds up in the bottom of the intercooler. When you tip into the throttle, that water gets sucked into the intake and causes a blowout of the spark.

Check for a TSB regarding the deflector plate or consider the 'small hole' trick that many EB owners swear by to drain the moisture.

2013 Ford F-150 Misfire Under Load - P0300 and P0306

Suggest a repair