I understand that if the MAF if unplugged or deleted, the ECU will run from a basic MAF table; perhaps the inlet manifold model? However, the ECU will be missing its primary input for determining how much air is entering the engine and therefore will not be able to set accurate fuelling, only relying on the STFT to make adjustments. If you've got a wide-band pre-cat oxygen sensor, then I suppose this won't be too much of a problem. Overall though, I should imagine that the ECU is more likely to err on the side of enrichment rather than enleanment to protect components so you will use more fuel across the board. The only problem I can think of with across-the board enrichment is cylinder bore-wash, but I think this is only a problem at excessive enrichment.

The ECU will probably be reasonably accurate with MAF predictions during steady cruise, but dynamic conditions will be more difficult to process. Idle is difficult enough to control anyway so I guess it depends on your typical driving conditions as to how much of an issue it is for you.

You should replace the MAF sensor as soon as possible.

Doug

Thank you all for your answers i understand that without maf i have to fine tune as possible the injectors but i am lucky that i have the MAP and wideband O2 i also have the stoch cat and i pass all emission tests succesfully. As for fitting some other aftermarket parts in my car thanks to this forum i can try to recalibrate everything is needed. Besides what you were mention before are there any other possible problems that i could have in the future?The protection maps work normaly? I also noticed that with this setup i can add an open loop BOV without any problems. Thanks again.