This could be caused by bad wiring but is usually caused by a weak coil. Change the plugs and install a new coil....I'd recommend doing all of them. This should take care of the misfire.
The engine cylinder locations are numbered : firewall 4 - 8 3 - 7 2 - 6 1 - 5 front I'm not a mechanic / technician but your misfire could be caused by a bad sparkplug , bad coil , fuel injector not allowing the proper air / fuel ratio , and maybe there are other causes of your misfire
Bad plugs, wire , or coil pack.
Bad plug, plug wire, burnt valve, blown head gasket, on that cylinder.
To fix a cylinder misfire on a 1997 Ford Expedition, first, conduct a diagnostic scan to identify the specific cylinder misfiring. Check the spark plugs and ignition coils for wear or damage, as these are common culprits; replace them if necessary. Inspect the fuel injectors for clogs or malfunction and ensure there are no vacuum leaks in the intake system. If the problem persists, consider checking the compression in the affected cylinder to rule out internal engine issues.
A cylinder misfire can be cause by a bad spark plug or a bad fuel injector. Replace the spark plug to see if the problem is corrected.
when cold runs fine holding tack at 2500 rpm then clears cylinder
To fix a misfire on cylinder 1 in a 1997 Subaru Legacy with a 2.5L engine, start by checking the spark plug and ignition coil for wear or damage, as these are common causes of misfires. Replace any faulty components, and ensure the spark plug gap is correct. Next, inspect the fuel injector for cylinder 1 to ensure it is functioning properly and delivering fuel. Finally, check for vacuum leaks or compression issues in the cylinder, as these can also contribute to misfires.
P301 is cylinder 1 misfire. The easiest fix is replacing the spark plugs, but the problem could also be cause by a burned valve or a malfunctioning injector.
Trouble code P0301 means: Cylinder 1 Misfire Detected
On a 1997 Ford Expedition ( 4.6 and 5.4 ) firewall 4 - 8 3 - 7 2 - 6 1 - 5 front of vehicle
If the check engine light flashes an engine cylinder misfire has been detected Avoid any heavy acceleration / decelleration and have the vehicle scanned for any trouble code(s) in order to diagnose and repair the problem
On a Ford Expedition : firewall 4 - 8 3 - 7 2 - 6 1 - 5 front of vehicle