Just use some RTV, silicone, etc. Clean the surface, apply and let sit overnight. Any air that can enter the system after the MAF is considered a leak because the MAF's job is to measure air volume entering. So if there is another source for entry the maths dont work out and the system is thrown a bit out of whack. Not saying this is your issue for sure but its certainly not helping. Ever drink with a straw that has a tiny hole in it?

Took it to my local LR mechanic, reset Adaptations, problem fixed. Thanks for the replies!

I tried a $15 one from Amazon. didn't work. Then my mechanic tried a genuine part from a spare LR3 he has and it solved the problem.

Recently had this also.
Replaced MAF with a genuine unit and reset the adaptations and light went away.
This was after trying with a cheap $15 unit from amazon, cleaning the throttle body (worth doing anyway as its easy), replacing PCV valve, new fuel cap and something else I cannot recall now (but was posted about on this forum). Pretty much I tried all the cheap options.

So, I would try with either a genuine LR MAF or perhaps try the Toyota one. Was a pain in the neck getting it sorted but really quite an easy fix.

No need for genuine when the Toyota one is the same. Or should I say Denso. There are times when getting "genuine" is the only option, but as with most parts Rover decided not to re-invent the wheel and go with an existing product. So a genuine part is just a re-package. Although I certainly understand hesitations but when the same part can be had much cheaper I would rather go that route and get more parts for the same buying power. Of course a $20 Denso MAF is probably a fake anyway. A genuine Denso MAF is about $100 USD with the Rover repackaged one costing no less than twice that. Any cheap unit is a gamble. So far I have been perfectly happy with mine and bought it mainly to see if it was in fact the issue. Literally first issue with the truck on the way home, a code for the MAF.

Of course the source of purchase is important too. I would never, ever buy a genuine car part from Amazon or eBay unless I knew the seller well enough. Fake parts comes two ways, super cheap (too good to be true price) or they shoot for the stars and even have fake packaging to sell the fake part at near full price. Low enough to be a good price and temp people though.

Agree. Totally. I guess I actually meant Denso because it was a Denso which was originally in my LR3. Of course, it may have been a replacement from the 'original'. Either way, the $15 gamble from Amazon failed!