P101 bane of my life

Good morning everyone this is my first ever post. I've just bought a 2013 2.2 110 Land Rover defender xs it's my dream motor!
The dream has starting to be niggled by a horrible fault light P0101 MAF performance issue.
I've had my pants pulled down at Taylor's in dumnow.
I gone to find a small split in my intercooler after a smoke test. Which has now been welded. I've had to remove the filter as this is the only way the light stays off! Soon as I put the filter back on the dreaded Light comes on it now sounds like I'm a boy racer as it's sounds like I have a dump valve fitted. I'm right in saying I have a air leak somewhere....any suggestions as I'm a YouTube mechanic!

hey there, nice tractor! Is there any green corrosion on the maf elements? It may have given up the ghost?

Good morning, thanks for such a quick reply I've just had a look and there's no corrosion, what so ever.
Just sounds like I've had a turbo dump valve fitted when I ecelerate.

Many thanks again

if you have just bought it? Take it back for them to look at. You shouldnt have any issues so soon??