I did try driving the car without MAF. Strangely no error codes or CEL's were thrown.
Unfortunately I won't be able to do data logging till the weekend.
Really??
I get an ESP light when my MAF is unplugged
Ok so I thought I would update on this. I did buy and install a new MAF 2 weeks ago. Maintenance more so than anything else.
Long story short, I got given a brand new replacement last week thursday. Which I promptly installed.
Drove a round trip of 1500km's this weekend. Averaging around 33mpg got it up to 36.4mpg for around 30 km's.
Then finally received my first check engine light. In fact the Camshaft position sensor had failed.
It however logged almost 700km's into the 1500km's trip. The engine light only came on around 1300-1400kms.
So the better part of 600km's there was a fault code but no engine lights etc.
I have ordered a new camshaft sensor. So I'm hoping the Original new MAF was faulty and the main cause.
But hopefully should see some improvement once the new camshaft sensor arrives.
Will keep updating as new information has been found or gathered.