jjsz:
The oem plugs are great, but they should be changed around 100k. We recommend the oem plugs as they are NGK iridiums, and will last every bit of another 100k.

The coil is probably ok, but hang onto it until you figure things out. You can move the cyl 1 coil to another spot after trying the new plugs. If the plugs don't do it, move the coil to another cylinder to see if the misfire follows.

Don

 

Buy a bluetooth OBD2 reader online.

Then buy AlfaOBD for your phone.

This will give you the ability to read every code your car might throw. Once you have the codes addressing issues is 10x easier.

 

Yessir, had the plugs replaced at 100,151 miles. SP143877AB

 

Excellent! Unless you have oil or other fluid down into the plug wells, with new plugs you should be ok.
A fuel cap issue should not affect engine operation. It can set a code and the CE light though.

Hopefully the installer did not damage a plug during the install.
Whenever you get a CE light, if the condition that caused does not remain, the light can go out after so many start/stop cycles.

Don

 

Try getting your own diagnosis tool. It's definitely going to work better than whatever AutoZone have (Amazon have a few)

Definitely Redo all your plugs and coils?(Try RockAuto for parts!)

But try moving the coil from #1 and swapping it to #2 and see if the misfires follows to #2(if it does then bad coil)