D5 (D5244T to 2005) Injector readings (MPG lower than normal)

[RPhoboS]

I'm just going through some tests to figure out why I've suddenly gotten worse fuel economy on my D5 (one particular journey is usually 57mpg - now is 37mpg).

I cleaned the throttle body, was really gunked up, just a lot of brake cleaner sprayed in, and gently cleaned with a mf cloth (no pushing the flap).
I'd assume the EGR and the rest of the intake is probably in the same state (140k miles).

Vida is reporting that glow plugs 2 & 3 aren't happy, so new ones will be installed tomorrow.

The MAF sensor was clean but I used a a little contact cleaner on it, without touching anything just let it dry out.

The MAP sensor was just replaced, the old one was a bit wet, oily - and the paint on the little thing dangling had come off (tbh I don't think there was anything wrong with it).
I'm wondering if the intercooler might need cleaning out or if it's leaking slightly, to replace it but no loss of power.

I just quickly did this test for the injectors, seems like 1 & 4 are the most out currently but not sure if that's a large percentage out ?

Appreciate any pointers