Numerous Fault codes P040200, P145E00, P029900

 I have just taken possession of another younger Fabia (current one is a 2004 1.2) I took possession of it last week. I knew it had several ongoing issues, I like a challenge and problem solving.  a MK2 2014 1.6 TDI  (55KW).

The codes are Po40200 (Active/Static) Exhaust Gas Recirc. Flow Excessive Detected, P145E00 (Active/Static) Mass air flow in regeneration operation too low, P029900 Turbo/Super Charge Underboost.

it's a project, time is not a factor, it's currently on SORN, and the MOT has expired,  I'm sure a few of you will have seen these codes before. wondering if there's a correlation to having all 3 illuminated similttanoiusly, I'm just looking for a few clues, I'm planning on removing the Turbo and EGR when I get time, when I start it up I find that it won't rev past 2,500 I know that it has had a timing belt last year Aug/Oct time ish, problems seemed to occur not long after.

My first step and for my own piece of mind, I'm going to check to verify for myself that the timing is spot on, then plan on investigating Turbo Actuating valve and movement, Turbo impellars and EGR valve (movement and actuation).

I'm sure there'll be one or two who think that I'm Mad - that'll be 100% in the right direction, however, it's these little challenges in life that give us the motivation to get up in the morning and and keep us entertained in the evenings trying to figure it all out 🙃🤪🤣 plus if muppets like me didn't come to your selves with stupid projects like this, we wouldn't have such a good forum with many issues highlighted and resolved, so, in a Perverse way, I'm providing a service to the forum by including you guys in my Stupidity 🤪🤣 and expanding other members the valuable lessons we'll learn together, my wife thinks I should be locked in a padded room, wearing pyjamas and quite heavily sedated - RUDE!