Thread: IX35 misfire ?

Morning all.
My wife called me at 3am saying her car was driving so badly and the check engine light was on while she was on her way to work today at the airport that she pulled over and called me. As this car burns oil and the oil sensor/light doesn't seem to work the first thing I did was to add 2L as I couldn't see any on the dipstick (the engine was still hot), Then I started it-engine light goes out but it felt like it was on 3 cylinders, idle-3000rpm felt the same, Apparently this is what it felt like before she stopped.

She complained of a shudder when it got a WOF and the mechanic changed the plugs about 10-20,000km ago and all was good.

So my questions are;
Could this be a coil pack ?
Buy 1 new coil and replacing each one until the misfire stops ? or just do all 4 ?
Is it worth buying an OBD2 tester to check the codes first ?

The car's is a 2014 IX35 2.0 petrol 210,000km Front wheel drive.
I'm mechanically minded, but cars have never been a strong suit for me.
It's parked on the roadside about 2m away from the fog line so I'm ok with doing a quick job on it there and then, the follow up question is; if the oil level was ok and I've now over filled it is that an issue ? I'm too old/round to fit under on the roadside to drain some. It's a 20km motorway trip so I'd have to call a tow truck.
Alan