RobC

Picked up a new MAF yesterday from the dealer. Price out the door was $219. Very straightforward installation.

I did MAF, torque, and boost measurements, but did it through 3 gears instead of just second.

Max MAF flow went up from 206 up to 248 g/s.
Max torque went from 312 up to 353 lb-ft.
Max boost dropped from 18 to 15.6 psi.

I find the drop in maximum boost pressure to be interesting. I thought it would have stayed constant compared to old MAF.

Time to go to the track again to see what difference this makes. Butt dyno says noticeable improvement and much more power from 5000 to redline now.

<img src="http://pictureposter.audiworld.com/199/mafnew.jpg">
<img src="http://pictureposter.audiworld.com/199/powernew.jpg">
<img src="http://pictureposter.audiworld.com/199/boostnew.jpg">

<a href="https://forums.audiworld.com/s4/msgs/838375.phtml">My old graphs</a>

veryfastS4

Rob, I'm not at expert with the internals of our car and wanted to know how you can tell if the MAF is problematic. Does the check engine light go on? or can this only be diagnosed through a VAG tool?

RobC

If your MAF is really out of whack, you will get error codes showing a lean or rich condition. In my case there were no CE lights, no errors codes, just a hunch that I was down on power. So when I measured my MAF rates and compared with other chipped S4's on AW, I found that my numbers were closer to stock (I'm chipped).

Install is very straightforward. The MAF sensor is located at the top of the engine between the air filter box and the Y-tube at the top of the motor. There are 2 clips that hold it on one end and a band clamp at the other. The only hard part is getting the flexible black intake tube back onto the MAF because of the tight fitting rubber gasket. Some patience and a very small flathead will help you get the job done.

There are others on here that are much more knowledgeable with MAF failures and symptoms. This is pretty new to me too, though I'm on the way to becoming an expert .

veryfastS4

The reason I was curious about this was because my friend who has an altima needs to get his MAF changed. His dealership was going to charge him $500 for the part and labor.
So being the curious and inquisitive individual that I am, I thought maybe I should look into that part on my car. How long did this take?

Wouldn't your MAF be replaced by the dealership for free? Wait, maybe not since you didn't see any error codes and dealership don't change things unless there are problems, right?

Nick Gustas

go get those mid 13s

RobC

Audi typically won't replace a part unless it's obvious that it's bad, such as error codes, etc. Plus they have begun to blame all kinds of failures on chips. I'll just bite the bullet and pay for it out of pocket.

It took about 2 minutes to get the MAF off, and maybe 10 minutes to get it back on. The first time I tried I didn't use any tools. I found that it was impossible to simply "press" the plastic tube onto the MAF due to the rubber gasket. So eventually I dug out a small flathead to help guide the rubber gasket over the MAF. On the S4 it should only take about 15 minutes.

On the Altima you will need to do a visual inspection to see where the MAF is. On my previous Maxima the MAF was at the top of the engine and probably would have taken about 20-30 minutes since much of it was bolted together.

mpwolf

You're only getting 2.5 samples per second. You can get about 3.3. Just go to the options screen and type in:

Blk Int: 25
Char Int: 0

Just like this:

<img src="http://www.ross-tech.com/vag-com/tour/screens/options.gif">

It will speed things up a bit.

Dangler {/KAWF} BUMP

Did someone say there's no MAF on a 2001?

DarinS4Turbo

Nope, just a better one that doesn't break all the time.

Prodigy

I concur