MAF

Thank you @Arctic2, yes, will keep it in mind and clean the MAP not the MAF with it.

Just my 2 cents. Solved my problem.

With maf plugged in I had hesitation before turbo kick in - quite dangerous sometimes as car felt like I am towing an elephant when trying to pull out. Run sweet with unplugged but knocked badly when cold and throttle was requested - read here somewhere that it is something to do with injection amount and time - detonation and all that stuff - didn't sound healthy so wanted to fix this.

3 mafs tested:
- aftermarket original to car (what the ron box used)- air flow was showing but no intake temp reading on scan tool. Car drove but badly. Rev rise very slow, dangerous to pull out, felt like labouring and barely could do 60mph without feeling that it is hurting. Cleaning didn't help. No knocking though.

- "New old stock" Bosch from ebay - £70 - same behaviour - showing air flow but intake temp too high by 25 degrees or so - run slightly better - especially when up to temp but a pain when cold - barely could get out of the driveway, still slow to pull out, 60 on the motorway where it felt least hurting. With this one mechanic with proper scanner said that the maf is "slow to respond". Cleaning didn't help. No knocking either.

- new aftermarket maf from JGS4x4 - £53 including next day postage. Air flow and correct intake temp showing - car is BACK BABY! I would risk to state that it drives as good as with the maf disconnected but without the drawbacks. 200 miles yesterday at 70 and the engine sounded like a sewing machine. Prod it and it was off to 80 and beyond so pretty happy with the result. Not sure how long it will last but happy to pay £55 once a year if have to.

Thanks.