Might try them, i'm just really worried that like my intercooler i'll swap it and i'll still have the problem knowing my luck

I changed the intercooler and my problems got worse and the car kinda drives like sh*te which is beyond me, as the intercooler is brand new, along with the MAP sensor.
It's beyond me as to why i'm in a worse situation once i've changed old parts for brand new parts? Can anyone explain why this may have caused me so much problems for changing to a brand new intercooler? As I was told by my mech that the intercooler was leaking so I had a boost leak which was causing me most of my MPG issues but now it's fixed the car is the worst it's ever been.
Even if the MAF was fooked before the new intercooler, then why the hell would my car get the worst it's ever been after changing the intercooler.
It's like for example; your spark plugs were fooked causing you running problems then you go change a tyre for a brand new one and suddenly straight after your car runs even worse? I just don't understand the boody car and my problems they make no sense what so ever. I'm sure you guys can understand why i'm so dubious about spending more money and getting the MAF changed for a new one cuz I may end up in a worse situation knowing my luck.
I'll check out that 24/7 parts thanks for the idea, much appreciated.
Can anyone shed any light on this problem i'm having as it's beyond me what's happened in the past year and £400+