Hello all, as seen in the title I have a 2000 mustang GT 4.6 throwing misfire codes for cylinders 1 and 5. Was driving fine and went to start up one day to a rough idle and terrible acceleration. Took a look and did the old test of unplugging other cylinder wires to troubleshoot. Found 1 and 5 to be the only two misfiring. Tried switching coils with other cylinders to no avail. Those cylinders still work with the coils taken from 1 and 5 with 1 and 5 still experiencing a miss. Have not yet tried the NOID test but planning to within a few days. Engine has a little over 200,000 miles on it, it sat for awhile before I bought it about 6 months ago. At that time, we put a helicoil in cylinder 5 and everything was running fine for around 4 months until now. Also has a brand new intake manifold and brand new spark plugs. Thinking it could be a wiring issue but not too sure. Weirdest part is both cylinders went out at the same time. Only vehicle I own so I would appreciate any help on diagnosing this misfire as I hate driving it like this, potentially damaging other components.