Solved!
Car has been running great, no more CEL or misfire.

Grease wars aside (I side with the conductive grease comment here), I'll provide a brief update on this:
I compression tested the engine this morning:
Cylinder 1: 180
Cylinder 2: 175
Cylinder 3: 175
Cylinder 4: 180
Cylinder 5: 180
So, that looks like a dead-end (happily).
I installed the new ...

Okay, I guess there's some consensus these symptoms could be caused by bad compression on cylinder 1, but would that really cause intermittent misfiring? I would think worn rings, stuck valves, blown head gasket etc. would manifest with a constant rough idle/misfire. The engine runs very smoothly ...

Thanks for the speedy response @DavidE7--I did try swapping the cylinder 1 coil out after replacement, no luck there.
I don't have a compression tester so haven't gone that route, but I would think it would run kinda poor all the time if I'd lost compression on cylinder 1...
I've had the cover that ...

Hi there,
I have a 2002 V70 XC with just over 100k on it (new to me in the last few months)
I recently experienced some intermittent stumbling/misfire. I read the codes and found it wasn't getting a signal from coil 1 along with the expected misfiring codes. Been here before, so I assumed the ...