Hi everyone, I am new to this site and this is my first posting. I drive an Octavia 1.9 tdi and it would seem that there is a problem with the MAF sensor. After reading several threads on this subject I tried disconnecting it. I drove from London to Lancashire with it disconnected and the Car performed much better. The car still lacked guts however and when on a steady uphill slope cannot seem to get much power and won't go much past 85 mph even with foot to the floor. I plan to replace the MAF but would be interested to hear if there might be another fault aswell or will performance improve with a new sensor? Also, can anyone tell me the purpose of the MAF sensor? If the car runs fine with it disconnected then why not just leave it disconnected? Any help will be much appreciated as I do that journey 3 times a month. Cheers all.

MAF = Metered Air Flow unit Basiclly it measures th air flow into your engine which in turn allows the ecu to to put in the right amount of fuel for the mixture. The reason why the car runs better with it disconnected when faulty is because the ecu has a set of measurements built in so it kind of knows how much fuel with however many revs (if you get me).

You can't leave it uplugged as it will throw a fault code and you mpg will drop as the ecu is really just guessing how much air and therefore fuel you need.

Hope this makes sense and helps you:)

The car will perform badly with the MAF unplugged, but if it's better than with it plugged in, replace it.

As above yes replace the MAF sensor.Might also be worth checking your Air filter too.

Thanks a lot guys. Obviously will have to replace the MAF.

Cheers again.

Check your hoses too and look for splits or hoses that have come loose.

I assume a diesel turbo will behave in a similar fashion to a petrol turbo if there's a boost leak.