Hi, new member here. We had a 2011 Edge that treated us great so we traded for a brand new 2016 3.5L Titanium AWD a few years ago and it was built on a Friday I think.... Anyway for this specific issue my wife was passing on the highway and the cel blinked under acceleration. Codes were 0300, 0303, 0304. We only have 57,000KM (35k ish miles) on it. I replaced the spark plugs, cleaned the TB and noted a lot of oil in the plenum so I changed the PCV/cleaned the plenum as well. We have run injector cleaner through it now too. When changing the plugs I moved the coil pack from #3 to #6 so if I had to change those 2 coils it wouldn't require taking the plenum off again.
When test driving now I can recreate the flashing cel by sticking the accelerator and the cel will flash when the engine redlines, if I immediately slow down I can feel the engine vibrating from the missing. The cel stops flashing and does not illuminate but it stores the same the 3 codes which seems strange since the cel turns off after the flashing. Previous to the plug replacement it would stay illuminated after the flashing. So moving the coil didn't move the issue but something changed the cel behaviour. I am leaning towards injectors but with such low km on the car I am kind of baffled it only happens at redline if I accelerate hard and stop before it hits 5.5k ish rpm no cel flashing. We haven't used it a lot with covid as we have 2 vehicles.
Any suggestions other than maybe swapping injectors and seeing if the problem moves cylinders? Thanks!