Air Mass Log Results

[Tutti57]

I have been getting a code for P0100 that could be a bad maf sensor so I did a log today following the Ross tech instructions.

My peak number was 167g/s. Does that sound low? They said it should be about 80% of your crank hp rating. That sounds like a stock reading, not a tuned one, right?

[Tutti57]

I found this morning that my idle fuel trim is -3.7% and my multiplicative value is between 9.5 and 10.5%.

I'm thinking my sensor is bad.

[shiro1745]

I have the same problem, here's some info here, two threads I started. I got a new MAF sensor but couldn't do any pull cause I have some other issues too. But you can see a lot of maf max values. Those are for Audi A4 B7, maybe it helps to get an idea.

http://www.audizine.com/forum/showth...MAF-max-values

http://www.audizine.com/forum/showth...lled-some-logs

[Tutti57]

I called Ross tech to discuss my readings and he said that he has never seen a maf sensor go bad on these cars and it was likely bad wiring or an air leak.

I am going to check for leaks this weekend and check the wiring.

That last post in the thread u linked it just like our problem but he never posted back if the new sensor fixed it! Damn him!

I wish I could swap with someone local just to see.

[Tutti57]

Rockauto has the cheapest sensor I've found for about $80. I'm not ready to order it quite yet though.

[Tutti57]

Oh sorry, I just realized that you were the op on those threads! What else is going on with your car? Have your trims changed since the sensor swap?

[shiro1745]

Unfortunately my car is down now, I'm trying to chase a gas leak in oil. I'll post results in the thread I started on audizine. I'll probably have some updates after this weekend, if not next weekend for sure, I don't have too much time for my car.

[Tutti57]

Ok sounds good.

[Tutti57]

Any updates on this?

[Tutti57]

I just went through and it seems like I am getting the appropriate power to the sensor but am only getting between 2.72 and 3.08 g/s at idle.

My fuel trims are still funny too at -3.1 and 9.5.

Has anyone ever seen a maf actually go bad on these cars?

[shiro1745]

If you look at the first link I posted you'll see that all users get anywhere from 2.5 - 4 g/s at idle, I wouldn't worry about that too much.

I don't have any updates yet, I'm hoping next weekend. But I'm not sure if my feedback will help you since I got new RS4 injectors and K0R turbo. I also did a carbon cleaning this weekend so I'm hoping everything will be fine with my car after everything is installed. I would bet my problem was clogged injectors, I tested them at 20PSI and they were not spraying mist, it was more like a jet. That caused gas getting into oil, so not all gas was getting burnt which I think cause lean condition(long time fuel trims +9%).

[cvincent78]

Did you try MAF cleaner first? It's possible someone sprayed silicone lube on the o-ring to make it connect to the maf housing easier and fouled up the sensor.

usually a bad MAF means bad MPG or poor to very poor acceleration / misfires at idle / lean fuel trim...

your part throttle fuel trim showing lean is a possible indication of many things.

[Tutti57]

I sprayed it with some maf sensor cleaner. Is that all you do to clean them?

I can't seem to figure out why p0100 keeps returning.

What other things could my fuel trim be indicating so I can start crossing them off my list?

Thanks