Q: Code p0301 replaces all 4 plugs, cylinder 1 and head gasket

Diagnostic Trouble Code P0301 means that Cylinder No. 1 is misfiring but the causes of that misfiring can be very varied. The fuel injector could simply be dead or there is little cylinder compression due to a burned valve or leaky head gasket. Even though you replaced the head gasket, cylinder compression should still be tested. Test for power to the coil as if there is no power to the coil the supply circuit (including the PCM) has to be diagnosed to find the fault. If there is power to the coil, I would check to see if the fuel injector is functioning and again check compression. You also have to rule out intake vacuum leaks at that cylinder. If you want these steps performed by a certified Mechanic, dispatched by YourMechanic right to your location, please request a misfiring diagnostic and the responding certified mechanic will get this diagnosed and resolved for you. If you have further questions or concerns, do not hesitate to re-contact YourMechanic.