Kilgore Trout is correct, it is an air straightener.
Until you put a supercharger or turbo on your car, it will not be any restriction. There are plenty of other restrictions that more than make up for any potential restriction of the MAF screen.
The MAF screen is used to minimize the "electronic noise" the MAF picks up due to air flow variations and oscillations created by bends in the intake tract.
If you take it out, you'll need a tuner to tweak around the noise variations by jacking up the hysteresis values in the program. In english that means you have to reduce the sensitivity of the MAF. Which means you end up compensating by richening at WOT. That means less power and more fuel consumption.
If you take it out, you won't lose or gain any significant power, but you will lose fuel economy and possibly some smoothness under acceleration.
People claiming that you gain power from removing it are only seeing a power increase due to the air/fuel ratio being leaned out from improper metering. Your are as likely to lose power from the computer trying to compensate for the "electronic noise" by adding fuel to ensure engine safety.
You are better off leaving it in place, you'll get no appreciable benefit from removing it, and potentially introduce the possibilities of several problems down the road.
As far as buying a new maf, just get one out of a wrecked car, you do not need an aftermarket MAF unless you are making serious power. The stock MAF is actually a very good design and can be tuned up to 400 hp naturally aspirated and can be tuned for different sized injectors. As far as physical restrictions, stock is 80mm (90mm in Lightnings and Terminators), unless you have a throttlebody bigger than that or you have a turbo/supercharger, the MAF will NEVER be a restriction - that is simple physics.
Bottom line, the only time you need to get an aftermarket MAF is when you have maxed out the voltage on the stock unit. Companies telling you that their MAF makes more power than stock in a stock application are doing so because they are selling you something to make money. They are "making power" by leaning out your air/fuel ratio using their "advanced velocity tubes". An aftermarket MAF will only work correctly if a tuner programs your ECU to correct for their so-called "superiority" to the stock MAF.
The legitimate MAF companies out their strictly sell a MAF on the basis of being able to meter a larger amount of air than the stock meter - which is what an aftermarket MAF is supposed to do. The only way to do that is a complete new resistor set. Those companies that tell you to re-use the stock resistor element offer no true increase in metering capability. A quality aftermarket MAF simply has a much larger range that can continue to meter beyond where the stock units max out, but all must be tuned specifically to your application. You'll rarely ever hear them tell you that their units flow more air than the stock units because it's not a real selling point. On the other side of the argument, what idiot would design a restriction into an aftermarket MAF?
In any case, the real selling point is the amount of air the meter can handle which is typically simplified using a max horsepower value. Some are larger than stock, but in virtually all cases the throttle body diameter (stock or otherwise), which is beyond the MAF company's ability to control, is smaller than even a stock MAF.
All that means is that until you are forced induction, the meter will almost never be a significant restriction. In fact I really can't see it becoming an airflow restriction prior to it maxing out voltage - and that is a testament to the excellent design of the stock meter.
Sorry to get up on the soap box, I hope i don't offend anyone. I just tell it the way I have seen it. I want the money you pour into your car to be well spent. If you are anything like me that money is hard earned. I learned all this only after I had purchased my third MAF. I certainly have no wish to be cheated out of my money and I imagine neither do you. If you would like some suggestions or any information please just ask.
