mass air flow sensor...

**blackmagic00** · 12-01-2007, 08:38 AM

what exactly does this do? my cars in the shop right now because its been running really sluggish. apparently my maf is bad and its gunna cost $300 to replace. i know it has something to do with the intake but is really that much or am i gettin ripped a new one? any input would be great!

**Jays00ss** · 12-01-2007, 08:56 AM

You can buy one for around $50 on ebay or on here in the classified section and change it yourself takes about 1/2 hour to do with common hand tools. Really easy to do.

**NeeD4SpeeD** · 12-01-2007, 09:23 AM

Originally Posted by Jays00ss

You can buy one for around $50 on ebay or on here in the classified section and change it yourself takes about 1/2 hour to do with common hand tools. Really easy to do.

He's right it's really simple to do and tell the shop to screw off for that price, grab a beer, throw on some tunes and take an hour and do it yourself!!

**180ls1** · 12-01-2007, 10:40 PM

it measures your air to fuel ratio you can get an aftermarket one and pick up a few horsepower also i believe slp has a pretty good one

**Wesman** · 12-01-2007, 10:55 PM

Originally Posted by 180ls1

it measures your air to fuel ratio you can get an aftermarket one and pick up a few horsepower also i believe slp has a pretty good one

Most people have nothing but bad luck with aftermarket Mass Air Flow sensors. The stock one is good to over 500HP, aftermarket sensors such as those from Granatelli and SLP tend to make the motor run lean and are a pain to tune.

You're best off with the stock MAF, thats one thing on these cars thats not worth upgrading.

**Olde Skoole** · 12-02-2007, 03:36 AM

MAF "Coldwire" Sensor
LS1 and newer engines use a "coldwire" MAF system where by the air passing over a tiny sensor causes inductance, this inductance is converted to a frequency which is then fed to the car's ECU. This frequency is related to the amount of air (CFM) passing over the unit, these MAF units have 3 pins, +, - and F, the F contains the square-wave frequency between - and F.

The mesh on the MAF is used to smooth out airflow to ensure the sensors have the best chance of a steady reading. It is not used for measuring the air flow per se and it is not recommended that you "clean" these units other than ensuring the wire-mesh is completely flat and free of any debris. Manufacturers claim that a simple but extremely reliable test to ensure correct functionality is to tap the unit with the back of a screwdriver while the car is running, and if this causes any changes in the output frequency then the unit should be discarded and an OEM replacement installed.
Courtesy of Wikipedia

**Benner** · 12-02-2007, 05:05 AM

I say screw gettin a new MAF. Ditch it and go with a speed density tune. I've got one and have never looked back. It uses other sensers such as map, IAT and your engine RPM to calculate how much fuel to throw in.

**Wesman** · 12-02-2007, 01:15 PM

Originally Posted by Benner

I say screw gettin a new MAF. Ditch it and go with a speed density tune. I've got one and have never looked back. It uses other sensers such as map, IAT and your engine RPM to calculate how much fuel to throw in.

Can't imagine thats very good fuel fuel economy though. Theres a reason almost every new vehicle comes with both a MAF and MAP, its called efficiency.

**Benner** · 12-02-2007, 01:22 PM

Actually it's pretty good. I'm pulling 28 MPG on long halls on the highway, and the lowest i've ever gotten was around 15 mpg, that was driving it like I stole it right after the new tune. That's with the current mods in the sig.

**Olde Skoole** · 12-02-2007, 04:45 PM

The MAP or Manifold Absolute Pressure Sensor is nothing more that a electronic Vacuum gauge, it simply measures engine vacuum and works with the TPS and MAF sensor to determine engine load.
Speed Density requires engine rpm and engine vacuum to work with it's pre-programmed, user-defined guidelines and is not nearly as accurate as a MAF equipped EFI system.
N-alpha fuel mapping only requires throttle position and engine speed to work correctly but is only used on motors with little or no engine vacuum at idle.

**sroach20** · 12-02-2007, 05:12 PM

Originally Posted by Benner

I say screw gettin a new MAF. Ditch it and go with a speed density tune. I've got one and have never looked back. It uses other sensers such as map, IAT and your engine RPM to calculate how much fuel to throw in.

do you drive yours in the winter? just wondering how it runs in the cold with the speed density.

**Benner** · 12-02-2007, 06:37 PM

When it's been sitting all night or enough for everything to cool to outside temp when its really cold, it runs a little rough in the morning if its really cold, but I let it sit and warm up for about 5 minutes anyway and after a minute or so it runs perfect (It's pretty much just that time when its in Open Loop (or closed loop I cant remember wich is at cold startup). I've had no problems with the tune and I'd gladly go this way again.

**SSTODD** · 12-03-2007, 07:37 AM

Originally Posted by Wesman

Most people have nothing but bad luck with aftermarket Mass Air Flow sensors. The stock one is good to over 500HP, aftermarket sensors such as those from Granatelli and SLP tend to make the motor run lean and are a pain to tune.

You're best off with the stock MAF, thats one thing on these cars thats not worth upgrading.

++1 Do not go aftermarket unless you want lean error codes.