Mike W

What's it really do? How might you know you need one? Will it affect performance? Cost? thanks

No HTwo O

If you needed one, I'd expect you'd have a CEL and fault codes. Performance would be down too. I think they are part of the emissions system. Cost about $762.00:

http://www.suncoastparts.com/product...Code=993ttmain

Mike W

I do , guess I need one, thanks for the help

No HTwo O

Mike, what codes do you have? Post them here. It may not be the MAS. You don't want to just start replacing parts, that are expensive, until you know what's going on.

I meant to say performance would be "down" not "done".

Basal Skull

AFAIK, The mass air sensor detects the amount of air entering the engine and is used to judge how much fuel to inject etc. I believe it is a hot wire and temperature sensor so that with more air, the temperature decreases/changes giving an indication of how much air the engine is consuming. On older cars it was simply a trap door that would open to allow air in and how much the door was open told the computer how much air was entering.

Quadcammer

As basal correctly noted, the MAF has a wire that is heated to a certain temperature. When the air flows over it, the wire is cooled by the air, and then the computer reads how much voltage is necessary to keep the wire at the pre-set temp. Typically once 5 volts is reached, the sensor is "pegged" and additional airflow cannot be measured. This is then paired with fuel tables in open loop operation (engine cold or at WOT), or 02 sensor data in closed loop operation, to give you the desired air fuel ratio.

The car generally runs quite poorly with a bad maf. Odd idle characteristics, stumbling at light throttle, poor performance, poor gas mileage etc can all be signs of a bad maf.

Before you replace it, try cleaning it with CRC Mass Air Sensor cleaner. If that doesn't help, skip right over suncoast, and purchase it here:

http://www.autohausaz.com/search/pro...0Mass%20Sensor

I just saved you $350

CincyScott

I've also seen where K&N filters (oil impregnated cotton) can do this, and cleaning the MAF often helps. I've not seen in on a Porsche, per se, but lots of other cars I've done work on. Hopefully, it's an easy fix.

Quadcammer

yeah, the oil from the K&N can get on the wire causing all sorts of issues.

Mike W

My wrench says I need one. Thanks for the lead - just bought one per your recommendation - ;saved some $$

Quadcammer

cool, hope it solves your problem.

good luck

Mike W

thanks agian, by the way I used to live in Passaic and work in Clifton.