It’s getting worse, but still no CEL.
I notice that when I let it idle in neutral, it does not misfire. When the idle settles down maybe 100 rpm from the time I stop (leaving it in Drive), it then starts missing, and it’s not rhythmic.
I will check for a pending code, though.
I’m wondering if an Engine Coolant Temp Sensor may also cause this. I had another symptom over the winter – hard starting when cold – that usually indicates an ECTS. Does that even make sense?
And I have been using 87 octane Chevron. Switched from 91 a few months ago.
At least the #1 cylinder is easy to get to. That’s a 10 minute job – five if I find the tools right away.