Misfires since install for diverter valve.

I would de tune the turbo and slowly bring it on back up. Off hand. Meaning to adjust the turbo actuator nut on the left hand side to loosen it up; Then one turn at a time (360degrees turn); toward the wastegate door or the hot side of the turbo. Each 360 degree turn is 2 pounds of boost; toward the hot side would be 2 pounds less, toward the cold side would be two 2 pounds more.
When I bought my turbo charger it was a Borg Warner. Stock S Mini Cooper turbo, But it was not the Full blown retail one. It was about 300 cheaper from a Turbo charger online distributer for fleet cars.truck,etc.
It was cheaper. And what I had to do is increase 180 degree's at a time the boost. Each time buttoning the car back up only without the heat shield. Then take it for a drive. It took a few hours. Until I found where it was by feel before.
You have a Hybird turbo you may have to increase the boost. But I would lower it to begin with until I feel that good old fashioned engine doing too much work and not enough turbo.
Today modern turbo engines are not designed to handle driving without the turbo working; unlike engines of yesteryear.
Thereby making it easier to spot when it does not have any turbo boost in it.
And also making it easier to spot when it is just right.
Hybird turbo's are pretty cool; in my opinion but more often then not These mini's suffer from not having enough fuel to gain large amounts of boost. Seeing how they are already boosted a good amount.
I think just stock it somewhere between 13-20 pounds of boost not real sure but even 13 is double the boost of older turbo cars.

Caltee123 said:

I’ve read up and it says that if cylinder 4 is misfiring it could be fuel filter because of lack of supply to cylinder 4 ? and it’s an intermittent fault and nothing else is showing up.

Click to expand...

So did it solve the issue? I would check the fuel tank return hose on the back of the valve cover and also the hose to the intake for fuel vapor return. Checking those for cracks. The idea that it is starving of fuel is out there. Unless you want to cut to the chase and get a new HPFP. Injectors. I'm sure it would make a difference in most applications. I personally still have my originals in mine. Genuine mini cooper injectors are about 5 times the cost of the other brand. At that point you have to tell yourself it's for a reason. Even though the lower end ones would probably suffice. It's just I have seen those lower end injectors from way back in the day. 2010 to be exact. And they were alot of money back then. They lost there value by half over the years to go along with the idea a lower end brand is not charged for being a real Mini Cooper Part.
So yea. when I need a injector I will get the real one and swap them around probably have to get 3 fuel injector install kits. Because that new injector is not gonna be going on the cylinder that had a bad one. Not at that price! It gonna where it needs to on the cylinder bank!