Does this have anything to do with moisture?

Scan for the codes when the engine light is on, then post the codes.

I had an issue with misfire and idling and running rough...at 55 mph it would stumble and jerk a little..was told 3 years ago ..could be the back coils...engine code misfire cyl 1. changed thr front coils 3years back. the problem only popped up occasionally. had the tune up and plugs at 80,000. ran good until just 7 months ago. started the stummble ..misfire thing..got too bad and had to remove intake and change the plugs and coils in the back...plugs had 135,000 miles on them...they were shot.car had been running really bad..new plugs..new coils..new intake gaskets..pcv valve and connections...215,000 miles..runs as good as it ever has..bought this car new..broke in with conv oil.. Mobil one at 5000 miles since new..oil light flickers now and ac just started leaking out. tranny rebuild at 135,000...great vehicle..