Three things are required for a combustion. Fuel/air, compression, and spark. Start with the cheap and work your way up. Coil and spark plug, fuel injector and fuel pressure in general, and compression. Swap the injector from #3 to a diff one, clear the code and see if the misfire follows where u swapped your injector to. If that doesnt work then do a leakdown and compression test but even then that can mislead.
I had the exact same problem on cyl #3 and it had the best compression! Turned out it was a head gasket fml. Since metal expands when it heats up it "filled" the gap that was in the head gasket and didnt let coolant drip in it while it was running but let it when it was off causing a misfire on startup
Whats your symptoms, miles, engine ect. Misfire on startup and it goes away, misfire while driving?
She says it doesn't feel rough like when it started. It was obvious she was on 4/5 cylinders while we waited on the ignition coils to be shipped. Now we just have a CEL, and no noticeable symptoms. I did get a new air filter while NAPA had their 70% off sale, will replace that too, no idea how old this one is. The spark plugs were replaced by the Honda dealership I bought it from, so I somewhat doubt that is it, unless they didn't know something about Volvo, which wouldn't be too surprising.
Its safest to just use oem volvo spark plus for volvos. They're very picky. If u take one out you'll know of it is or not. It'll say volvo on the side with three prongs on the top. Otherwise pursue the options i listed above. Usually a misfire will be something simple rather than what happened to me.
Yes, I would definitely check the spark plugs! It is not hard to do and it will give you a piece of mind knowing what they put in there . . . I would also asked myself why have they change the spark plugs in the first place . . . maybe they noticed something already and thought changing the plugs would fix it.