Ah you have a decat, I missed that on the first read through.
If the remap didn't include coding out the post-cat O2 sensors, that can and usually does throw the EML against a 'catalyst efficiency' fault. The engine ECU compares the O2 sensor readings in the downpipe to the O2 sensors behind the secondary cat (which you no longer have) and if they disagree with each other, you get an instant EML, which is why they need to coded out. It's just a simple on/off setting in the base map.
Do you know who remapped it? If you do, might be worth asking if they did that. It's standard on most Stage 2 maps, but tuners like Revo leave the standard O2 maps in place on Stage 1, so if it's stage 1 and the cats are binned off, it will EML.
Excessive carbon build up will cause cold misfires, as will swirl flap deletes.....although some tuners have a specific map to correct that. Do you know if yours has had a swirl flap delete?
As for injectors, they only misfire at idle and low rpm when they start to fail, but as yours is missing at 3.5-4K, it could be fuel flow that's the problem as that is the peak boost rpm, which demands the most amount of fuel. Has your HPFP got uprated internals in it? Seems like you've got some fuel short falls. At that rpm and full throttle, you should be seeing 109.9 bar on a standard map, 115-120 bar on Stage 1, and 125-130 bar on Stage 2.