PDA

View Full Version : Bad MAF sensor??



6berry
03-08-2011, 03:29 PM
Today i cleaned my air filter and my MAF. both were very dirty and i cleaned the air filter with water and cleaned the MAF with a dry paper towel. when i put the MAF back in and started my car it stuttered really hard right when i started then was stuttering a little while i was driving. is it possible that I messed up my MAF sensor? if it is where is the cheapest place to find a replacement?

Seerlah
03-08-2011, 03:39 PM
How did you clean your MAF? And you are supposed to replace your stock filter, not clean it. They are only like $10. If it were an afternmarket oiled one, then you would clean and re-oil that one.

And how exactly did you clean your MAF with a paper towel? The black casing isn't what you are supposed to clean, as that is exactly what it is. A casing. If you look inside the MAF, there is an element that reads air measurements. It is located directly under where the connector is (sits in the middle of the MAF). You are supposed to clean that (don't ever touch it), with an auto product specifically designed to clean your MAF.

http://www.google.com/products/catalog?hl=en&sugexp=ldymls&xhr=t&q=crc+maf+cleaner&cp=6&bav=on.2,or.&wrapid=tljp129962747571808&um=1&ie=UTF-8&cid=16599276143063779391&sa=X&ei=1b12TY-dMMrZgQee8KXDBQ&sqi=2&ved=0CCcQ8wIwAg#

You can pick it up at your local Autozone. And I hope my post didn't come off in a rude manner. It's just there is a proper way of doing things.

Edit: Just saw your mods and noticed the CAI. Please excuse the part of the panel filter replacing.

Audi Skate Snow
03-08-2011, 03:40 PM
It is possible that when you cleaned the AIR filter there was still water in it and it got on the MAF.

Best thing you can do at this point is pull both back off and clean the MAF with proper MAF cleaner or electrical parts cleaner. All you need to do is spray the sensor directly inside and let it dry completely before putting it back on.

EDIT.. noticed the CAI as well. Do not use any oil based cleaner when cleaning the filter.

Seerlah
03-08-2011, 03:48 PM
After you clean the MAF properly and the misfires still occur, unplug the MAF. If the misfires stop after you unplug the MAF, then it needs replacement. And no, it isn't good to run the vehicle with no MAF (you will be runing rich). But, you can drive it that way till you get a replacement.

People like to crap on ebay, but I found some incredible deals on there. My current MAF I bought for like $85 shipped was sourced from there (brand new Bosch OEM unit).

6berry
03-08-2011, 04:17 PM
i cleaned the element part of the maf with a paper towel. i unplugged it and it ran better so does that mean i need a new one?

Seerlah
03-08-2011, 04:21 PM
Did you try the CRC MAF cleaner yet? I would try that first. If the misfires continue afterwards, replace the MAF.

6berry
03-08-2011, 04:29 PM
ill try that tomorrow

NeedingAnAudi
03-08-2011, 06:21 PM
My maf went bad, that would cause the car to go into limp mode correct? I have absolute no boost, feels like a damn civic

6berry
03-08-2011, 09:14 PM
i didnt drive with the maf plugged in. i could plug it back in tomorrow and tell you. i unplugged mine and now im only getting around 4 pounds instead of 6 pounds of boost

NeedingAnAudi
03-08-2011, 09:35 PM
I had to drive with mine unplugged, with it plugged in I was running very very rich, about 3 times more fuel that I was supposed to be getting. When I was driving home the car was a complete dog, very unpleasant for sure.

my 1.8t
03-09-2011, 12:34 AM
i had my car ran the other day for codes and i had 2 misfires. im haveing a very ruff idle also. do you or anyone think this may be my MAF sensor? i also checked all coil packs and have new plugs and still does it. im stumpped can anyone help or have any input.
I had to drive with mine unplugged, with it plugged in I was running very very rich, about 3 times more fuel that I was supposed to be getting. When I was driving home the car was a complete dog, very unpleasant for sure.

Seerlah
03-09-2011, 02:03 AM
^You should start a new thread, asking about your compression issues (be specific in the title to grab attention).

To the OP, I forgot to say that you won't be able to boost with the MAF unplugged. You are basically in limp mode, because the ECU can't take accurate intake air measurements for you to boost. If the ECU brought in more air with the ECU not being able to measure it and add fuel accordingly, then you would run incredibly lean and detonate your engine. The ECU is cutting off boost via n75 valve and basically having you run rich since it can't calculate correctly without MAF readings, but that too is not a good thing. But it is better to run slightly rich, than it is to run lean.


My maf went bad, that would cause the car to go into limp mode correct? I have absolute no boost, feels like a damn civic

Having a faulty or defective MAF will make you run lean. The car will be placed into limp mode if runing lean. But in my experience, I had misfires before anything. And replacing the MAF does not automatically make you come out of limp mode. You need to reset the ECU to get out of it. There is the VAG Com method, or negative terminal/ECU removal method.

BUK_DAA
03-09-2011, 03:14 PM
so how do you know if your in limp mode without a boost gauge? can you check with the ebay vag com? and what is limp mode? is it just a safety mode? sorry for the questions, its just that i just replaced my maf today and coincidently this post came up

Seerlah
03-09-2011, 03:29 PM
so how do you know if your in limp mode without a boost gauge? can you check with the ebay vag com? and what is limp mode? is it just a safety mode? sorry for the questions, its just that i just replaced my maf today and coincidently this post came up

You should get a boost gauge.

If you have a Vag Com with software, you can log to see how much boost you are getting by logging (or simply looking at) block 115. This will list in mbar what you are actually boosting and what your ECU is requesting. But really, get a boost gauge.

Limp mode is a fail safe the engine's ECU will place you in if you are running lean, by limiting boost to 5psi. This will be controlled by your n75 valve, which is the stock boost control valve.

NeedingAnAudi
03-09-2011, 05:29 PM
Having a faulty or defective MAF will make you run lean. The car will be placed into limp mode if runing lean. But in my experience, I had misfires before anything. And replacing the MAF does not automatically make you come out of limp mode. You need to reset the ECU to get out of it. There is the VAG Com method, or negative terminal/ECU removal method.

I guarantee you that I was running waaay rich. I had vag com hooked up with the maf running, and the injector pulse and maf reading tripled when it was plugged in. When I disconnected the maf the pulse went back to normal since the maf reading was now based off the ecu.

Seerlah
03-10-2011, 01:44 AM
^I am not doubting you. Never said that I did. I was just taught that the ECU will make you run "slightly" rich to preserve the engine, with it unplugged. Pardon if I am incorrect.

NeedingAnAudi
03-10-2011, 03:10 PM
^I am not doubting you. Never said that I did. I was just taught that the ECU will make you run "slightly" rich to preserve the engine, with it unplugged. Pardon if I am incorrect.

Ok, I'm just thinking maybe other ecus might do that. With it unplugged I do think I am running rich however, when off throttle it is definitely backfiring

jeffrey146
03-31-2012, 10:46 AM
Something else that could cause you to miss fire. I bought my a4 with 200k on it. I decided to replace the spark plugs. Turns out they where either replaced once or never. Before, when you pressed the gas really fast it would make a crackling noise. I suppose the gas wasnt igniting in the cylinders. That might have been what caused the O2s to fail. IDK.

question: im still showing some "powertrain errors " in the obd2. Should I replace the plug wires & or the coils? The errors are P0133 & P0441. I believe the 0441 is an 02 slow feedback that im not worried about.