I have a 1997 Ford Thunderbird with 4.6 engine, 144K miles. I had to step on the gas to make it onto an expressway entrance ramp and the engine shuddered, running rough for next 1/4 mile then cleared up. Service Engine Soon light came on.
Took to Autozone to read trouble code 304, which says #4 cyl misfire.
Since the event cleared, what is best course of action if any? I thought that adding a bottle of Tecron fuel system cleaner couldn't hurt but as far as the ignition, and checking continuity on #4 spark plug wire, not sure what I should check to resolve if this happens again. All 8 spark plugs were replaced in last year, but all original wires and ignition coils/modules.
Thanks.