I replaced spark plugs because of a misfire in cylinder 2 and it ran great no issues for two months now a misfire in cylinder 2 again what could be the cause?

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Check to see that plug wire is fully seated on plug and coil pack..Then, pull plug to see if fouled due to not firing when pack was bad.

Timing could have jumped. Could be a bad head gasket also. even possible to be a small hole in piston check the cylinder for compression. Check the fuel injector to that cylinder if you have bad air to gas mixture it will throw a code of misfire change fuel filter check fuel injector to see if clogged. most likely it is the fuel injector .

What DTC code(s) are you getting?
You performed a compression test on cylinder #1; did you test cylinder #2?
Compare the readings, if there is a significant difference in compression readings between the two, you may have a bad head gasket, a bad valve, etc.
The bottom line, the problem is internal to the engine.

run a compression test on all cylinders to rule out head gasket or burned valve.

The injector is bad , internal coil when heated shorts out . Feel lucky it's only one injector . It could be like this corvette all injectors Quit when hot ! Test the injector with ohm meter . Chevy Corvette No Start When Hot The Diagnosis

check your wires they may be frail. also check your spark plugs they may not be gaped right.

Did u find code p0306 comes up ? Two things can cause this if the plug and coil have been replaced.the intake manifold may be leaking in the area of cyllinder 6 or its a mechanical issue.try doing a cyllinder misfire test and also check the compression on all cyllinders

Replace the coil for number 3 cylinder.

ignition mod. grounds,pcm or timing belt could all be it but, I would have to look at timing first.