And I'm back in the thread again...
Last year was misfires on all 4, messy but driveable, one shop diagnosed it as the turbo wastegate sticking and wanted to replace the turbo, I replaced the spark plugs and it ran fine.
Until now.
Overboosted and got that cel, then a cylinder 1 & cylinder 3 misfire. Cleared it, and #3 continued to misfire, sometimes just running rough but not enough to trigger the cel, sometimes enough to trigger the cel then good enough to clear it. It then moved to misfiring so much it was more of a not-firing issue. Faint gas smell at the engine, particularly on that bank. Nothing like fuel spraying everywhere or anything that dramatic though.
I suspect injectors, maybe something leading up to that in the fuel delivery department, but will be investigating all the usual, and cheaper, suspects first.