D13 460 slow response

Hello everyone,
I have problem with engine slow response. It takes time to build boost and its bit low on power.

Engine is D13C, 1 mil km.

Everything started when spring broke on no5 injector. While mine injector was sent for repair I put in used injector from other d13 engine to keep me on the road.

At that time I did not had PTT to put new injector code into ecm so I was driving like that, throttle response was slow, i had code for low boost but truck was rolling and I was waiting for my injector to come back from repair.

After some time my original injector finally came and when I swapped it I was hoping truck will run normal like before because its original injector is now back on its place but it did not happen, only low boost code went away.

In the meantime I got into possession of volvo ptt and reset learned data and things got much much better but it's still not like responsive like it used to be.

Also truck is using less fuel, before all this happend I had consumption of 32L/100km and now I have 29L/100km.

My opinion is that this problem is only on software side but I'm listening for other opinions and options.