Hello There!
So, I have a 98' V70 non turbo (2.4L) with 240,000 miles
My oil filler cap was leaking oil down into the spark plug area a couple months ago. Most of the cylinders were reporting misfires. I assumed this was because of the oil. I replaced the oil filler cap and did a full tune up on it (spark plugs, sparkplug wires, dist. cap, rotor button, fuel filter). It was due for it. The misfire codes stopped being thrown for about three weeks after that.
Now they are back on.
Current codes
P0300 Multiple/Random misfire
P0302 Misfire in cyl. 2
P0304 Misfire in cyl. 4
P0305 Misfire in cyl. 5
P0503 Misfire in cyl. 3

I am at a loss. The car is not running poorly, but I don't want to damage it by continuing to drive it all of the time with so many reported misfires.

It is also throwing
P0455 emissions (gross leak)
P0102 Mass air flow

I don't know if those are relevant or just a separate issue.
I would love any insight Y'all have. This forum has been extremely helpful in the past!
Thanks so much for your time!
Pip