i knoe it has sumthin to do with the intake, but what is it and what does it do?

 

MAF = Mass Air Flow Sensor. Its this round thing in the intake trac. It has like this little sensor that lets the computer know how much air is coming in so it knows how much gas to put into the Air Fuel mixture. I think thats what it does any ways :oops:

 

Look under "Technical Articles":

http://www.autoshop101.com/

 

Your MAF (Moody and Fragile) sensor is this delicate piece of expensive ($171.00) plastic. Its only function is to prevent you from adding an aftermarket intake, unless it is an AEM intake that was installed by the dealer.

The factory MAF will punish you if you install any other brand (the dealer has a supply of stronger MAFs that they secretly install as part of the AEM install which ensures that an AEM-equipped engine will run fine) by pinching off the fuel supply making your engine idle rough and unable to rev over 3000 rpm.

 

Are you serious? That may explain why my intake gave me problems.

 

is this true?

 

That's not true. I worked at a toyota dealership for 7 yrs. Never heard of that.

 

Haha... I thought I was a conspiracy theorist!

 

The real reason an aftermarket CAI (specifically the short ram style) usually causes the MAF sensor to foul is because the oil from the air filter gets sucked into the intake and gets stuck to the sensor. The AEM intake is really LONG which lessens the chances of this happening (if you notic, the TRD intakes for the Corolla/Matrix are also long like that).

-Alex
Purveyor of "secret" parts (that's why my xB has 350 hp at the wheels )

 

The MAF is a sensor that uses a heated wire to measure the amount of incoming air. The incommiing air cools the wire and changes the electrical resistance. The ECM constantly reads this value along with other inputs and determines how much fuel to add.
The wire used in the MAF is also heated up to burn off any debris or oil.
When you change the intake track before you MAF, you run the risk of getting false readings depending on the design of the MAF.
Some MAFs use a screen in front to smooth out the incomming air for a better reading. Many hot rodders remove the screen because it restricts the flow. This causes bad readings at different loads and can make the car run worse. The MAFs without screens are dependant on the design of the intake pipes and filter to get an accurate reading.
In other words, you need to know what you are doing to get additional power.

 

mikem53, isnt takeing the screen popular with c5 vettes?

 

Yes... In fact on my 04 Z, GM removed the MAF screen. Many who have added intakes are getting error codes and have removed them. The others who have removed the screens usually end up with a lean condition. Many have to reprogram the ECM to fix this...

 

If i was to remove the bottom 1/2 of the AEM intake tube so the cone sits in the engine bay to reduce water and dirt splashing in, would it raise the chance of ruining my MAF sensor since the cone is now so close?

 

maybe but plenty of intakes do this (run the MAF relatively close to the filter)... and i haven't heard of problems...

and the placement of the filter is really not such that contaminents would get in. (i.e. its not in a place where water and gunk would easily reach). Also its the same location that the bypass valva would potentially be drawing air from... so I'm pretty sure the MAF is safe there.

if it weren't such a pain, i'd seriously consider removing the lower half to see if there's any difference... oh well maybe sometime in the future.

oh also if you remove the lower half... it'll be remarkably similiar to the injen short ram for the xA...

 

The problems with the MAF is precisely why injen has added a little inline filter on the intake.

 

The reason aftermarket intakes cause problems is that most of them are designed poorly and cause turbulence around the MAF sensor. The meter gets hit with waves of turbulent air versus a constant flow on which good intakes have.

MAFs are a pain in the ___ if you increase injector size, you have to increase the diameter of the intake pipe so it "scales" proportionately with the injectors. Also the distange between the throttle body and the MAF sensor has a HUGE effect on performance...some people compensate with a poorly designed system by putting the MAF sensor as far away fromm the throttlebody as possible.

 

when i installed my intake, i feel as if my MAF wires are kind of tight and are be pulled everytime the intake shakes or rattles a bit. is there anyway to give the wires going to the MAFS some more slack?

 

OMG!!!....

Alright....The maf is a calibrated unit that measures the incoming air and in the newer units like on the xA/xB incoming air temperature. The unit is calibrated by Toyota so that it measures the incoming air and works together with your O2 sensor to acheive a proper air-fuel ratio.

Now.... On good aftermarket intakes some of them are the same diameter sizing of the original piping all the way through, and others are a larger diameter before and after the maf and a small section where the maf sensor is is kept the stock sizing. This is used so that your computer will be gettin an accurate reading of the incoming air. If you go with a larger diameter tubing where the maf is, or use a cheapo ebay intake they run a larger piping end to end. What this does is allows for more unmetered air to pass by the maf sensor, throwing off the stock air-fuel mappings, which is picked up the your O2 sensor. Your computer tries to compensate but since its not reading alot of the incoming air it throws the check engine light because it sees this a problem. Most aftermarket intakes that are larger end to end offer computer reflashes(like on popular american pickups, corvettes, mustangs) that reprogram the computer to get better readings. What aftermarket companies for our cars are doing is keeping the stock sizing by the maf sensor so the computers are happy, and what increase in airflow you get with your intake the computer will compensate for it as intended. They do this large in part for 1) ease of use by the average joe and 2) one of the biggest reasons is that its vurtually impossible for aftermarket companies to hack into the Toyota computers to change what need to be changed. That's y alot of people running boost on these cars go with a piggyback unit.

Hope that clears things up.