The correct gap is indeed 0.039 - 0.043 (1.0 - 1.1 mm). I would re-gap them back to the correct spec.

If the misfire returns and the replacement/swapping of the coil packs and plugs haven't fixed the issue it's time to look for other causes.

If you are finding oil on any of the plug threads replace the valve cover gasket. Perform a compression test on all the cylinders. They should be within 10% of each other.

Other possible causes: Bad fuel injector (not very common), cracked exhaust manifold (very common). To see if the manifold is cracked remove the heat shield surrounding the O2 sensor.

1998 Sportage - Gone.
2004 Honda Civic Coupe.
2007 Suzuki Grand Vitara - She got it.