Question

I have a 2006 Ford F150 XLT and I have the P0357 engine code. I tested all my coils, and they are all good. What else could give me this code? thanks

Answer 1

P0357 Ignition coil primary / secondary circuit

The sparkplug boots allowing the secondary ignition to  ground and causing the misfire, this is what you need to look for or just replace the sparkplug boots.

Answer 2

P0357 Ford Code - Ignition Coil 'G' Primary/Secondary Circuit Malfunction
Read more: https://www.autocodes.com/p0357_ford.html