2002 WRX MAF Question
08-14-2004, 12:13 AM
#1
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Posts: n/a
2002 WRX MAF Question
How Sensitive is the MAF sensor? What are the chances of damaging a MAF by removing it and installing it in another car?
I am getting the P0171 CEL, A/F lean bank 1, The Dealer says my MAF sensor is bad although there are no MAF CEL codes listed.
The dealer is saying that I caused the problem by removing the AirBox in the fender and using a K/N replacement Panel Filter. The only two mods I have done. The dealer won't cover it under warranty.
I don't trust the dealer, this is the 4th time it has been at the dealer for the same problem. So I wanted to borrow my friends MAF from his WRX same yr/model to see if the CEL clears. My Friend says the MAF is to fragile and it might get damaged. If that is the case so be it, I will buy one and try it. If not, I would like to use the BUL$HIT card on him so I can save a couple hundred bucks on a maybe fix.
Thank you for your help
I am getting the P0171 CEL, A/F lean bank 1, The Dealer says my MAF sensor is bad although there are no MAF CEL codes listed.
The dealer is saying that I caused the problem by removing the AirBox in the fender and using a K/N replacement Panel Filter. The only two mods I have done. The dealer won't cover it under warranty.
I don't trust the dealer, this is the 4th time it has been at the dealer for the same problem. So I wanted to borrow my friends MAF from his WRX same yr/model to see if the CEL clears. My Friend says the MAF is to fragile and it might get damaged. If that is the case so be it, I will buy one and try it. If not, I would like to use the BUL$HIT card on him so I can save a couple hundred bucks on a maybe fix.
Thank you for your help
08-14-2004, 12:32 AM
#2
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Join Date: Feb 2004
Location: The Hunted Forest
Posts: 720
Car Info: Mazda Protege '02 (Wishing protege has AWD and a H6 twin turbo)
These maf's are thick film type and are fairly robust compared to the heated wire kind with is brittle.
Just don't drop it ok?
The dealers crap about the k&n being the problem is crap. Maybe another dealer will be less picky.
Just don't drop it ok?
The dealers crap about the k&n being the problem is crap. Maybe another dealer will be less picky.
08-14-2004, 08:04 AM
#3
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Join Date: Nov 2002
Location: Baltimore, Md.
Posts: 36
Car Info: 2002 Black WRX
Should be no problem
I have an 02 with K&N and removed silencer. It has been that way since almost the beginning, no problems, just dirty MAF.Have you cleaned it yet. If you search the boards there was a discussion about the correct kind of alcohol to use to clean the MAF. I just set it in a large zip lock and poured in some alc. then gentle shake. Let dry. reinstall.
Maybe try a different dealer.
To answer your original question Road Spike is correct.
Silly
Maybe try a different dealer.
To answer your original question Road Spike is correct.
Silly
08-14-2004, 08:15 AM
#4
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Posts: n/a
Re: Maf
Thanks for the MAF cleaning info. I have had the K&N on the car the second month I owned it and did the Air Box Mod about 2 years ago. The Dealer's just being a D**K. The Probelm with Subaru is the Dealers are too far apart. The Next closest one is about 15 Miles, Doesn't sound like a lot except when you live in LA and it can take 2 hours round trip not to mention wait time for them to do the work.
I will try Cleaning the MAF.
I will try Cleaning the MAF.
12-21-2004, 06:27 PM
#5
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Location: College Park, MD
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Car Info: 2002 Wrb WRX sedan
Regarding the cleaning what should I see afterwards? what I mean is that when I look in there now (assuming its dirty) I see the two wires coming across with what looks like tubes covering the wire in the middle. what should see after its clean? I don't want whatever that covering is to be taken off my the cleaner.
Todd
Todd
12-23-2004, 09:49 AM
#6
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Join Date: Nov 2002
Location: Baltimore, Md.
Posts: 36
Car Info: 2002 Black WRX
its been a while
It has been a while so my description may suck. At the sensor end is a tear drop type of thing. If it is dirty it will appear just that Dirty. Follow the procedure above. the alcohol and gentle shaking will knock the dirty loose it will not hurt the sensor at all. Just use the correct kind of alcohol, which any good electronics store will have. good luck.
12-23-2004, 12:17 PM
#7
Originally Posted by wrx2themaxx
. My Friend says the MAF is to fragile and it might get damaged. If that is the case so be it, I will buy one and try it. If not, I would like to use the BUL$HIT card on him so I can save a couple hundred bucks on a maybe fix.
Thank you for your help
Thank you for your help
12-23-2004, 04:03 PM
#8
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This link shows you how to clean the MAF http://spydermagazine.com/2002/March.../maf_clean.htm
12-31-2004, 03:37 PM
#9
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Location: Phoenix, AZ
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Car Info: Subaru Impreza WRX 2002
Originally Posted by SillyAssKilby
It has been a while so my description may suck. At the sensor end is a tear drop type of thing. If it is dirty it will appear just that Dirty. Follow the procedure above. the alcohol and gentle shaking will knock the dirty loose it will not hurt the sensor at all. Just use the correct kind of alcohol, which any good electronics store will have. good luck.
01-02-2005, 02:29 PM
#11
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I used a CRC brake cleaner see here: http://www.usahardware.com/inet/shop...cals/05088.htm
It seems to have worked fine. I don't have any problems and idle seems a little better, but that might just be my spark plugs.
Todd
It seems to have worked fine. I don't have any problems and idle seems a little better, but that might just be my spark plugs.
Todd
01-04-2005, 09:08 AM
#12
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bottom line, oil from oiled filters CAN deposit on the MAF sensor.
there are two elements in the maf sensor housing: the IAT and the MAF sensor itself. when you unscrew and remove the sensor housing, the little "bulb" thing is the IAT. that must be clean. it's hardy--use a q-tip.
also, UP INSIDE THE MAF SENSOR HOUSING is the maf sensor wire itself. that is NOT hardy, and very fragile, and should NOT be directly touched. the non-chlorinated brake cleaner is the proper solvent to use. it is primarily tolulene and xylene and acetone, which of course could be used in its place if you have them around in liquid form.
the code is thrown when the fuel trims max out. the fuel trims are set by the ecu after comparing the front o2 sensor output, and the MAF sensor output. if either of those signals is thrown off--either by a dirty MAF, IAT, or bad o2 sensor--then you'll eventually get an AF MIL.
hth
ken
there are two elements in the maf sensor housing: the IAT and the MAF sensor itself. when you unscrew and remove the sensor housing, the little "bulb" thing is the IAT. that must be clean. it's hardy--use a q-tip.
also, UP INSIDE THE MAF SENSOR HOUSING is the maf sensor wire itself. that is NOT hardy, and very fragile, and should NOT be directly touched. the non-chlorinated brake cleaner is the proper solvent to use. it is primarily tolulene and xylene and acetone, which of course could be used in its place if you have them around in liquid form.
the code is thrown when the fuel trims max out. the fuel trims are set by the ecu after comparing the front o2 sensor output, and the MAF sensor output. if either of those signals is thrown off--either by a dirty MAF, IAT, or bad o2 sensor--then you'll eventually get an AF MIL.
hth
ken
01-04-2005, 07:38 PM
#13
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Thanks for the info, that's my experience as well. However, I used electrical contact cleaner, not brake cleaner... acetone degrades plastic (a friend of mine who used to make boat hulls used acetone to etch plexiglass and clean epoxy off of brushes, and my wife uses it to clean up acrylic paint; it comes in a can with a metal cap, not a plastic one!). The entire MAF housing and assembly is made of plastic, as is the gasket and the covering on the wiring.
The electrical contact cleaner I used is specifically designed to be safe on plastic, has zero residue and worked really well. I'll post some before-and-after pics tomorrow.
The electrical contact cleaner I used is specifically designed to be safe on plastic, has zero residue and worked really well. I'll post some before-and-after pics tomorrow.
01-05-2005, 12:30 PM
#15
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Well, no pics, as I can't find the special USB cord I need to hook my camera up to the Mac. Guess that means a trip to Best Buy... 
Anyway, the stuff I used is called PureTronics electrical contact cleaner. The main ingredients are Xylene, ethanol and propane. I removed the MAF assembly and wiped it down with a slightly damp microfiber rag (dust had made it past the O-ring, gotta love living in Arizona). One quick shot of the cleaner and the little orange bulb of the IAT was clean as a whistle, but I *very gently* wiped it with the microfiber cloth to be certain. I then angled the housing over the sink and gave the MAF sensors themselves (two tiny wires that look like diodes) a big long shot of the cleaner, letting the excess run out of the "tunnel." I didn't see a big difference, but considering how well the stuff cleaned up the IAT, I'm certain that the MAF is now clean.
I let it sit for about 10 minutes so the last of the ethanol would evaporate, and then I reinstalled it, appling a tiny bit of silicon lube to the O-ring just for kicks. I've driven it for about 60 miles since then with no CEL and no major changes in car behavior, so it probably wasn't that dirty in the first place.
BTW, I've been using an oiled filter (Perrin foam) for about 14,000 miles, and I didn't see anything that looked like oil on the MAF itself, nor did I find any oil inside the airbox on the post-filter side or inside the actual intake. I re-oil the filter every 2,000 miles or so, but I am always very careful to blot the filter and massage the oil deep into the pockets of the foam. The reason I went with an oiled filter was because I live in Phoenix, AZ -- not only is it incredibly dusty here, we also have poor air quality (microparticulate count) 3 months out of the year. Also, because we get rain so rarely, brake dust and car exhaust actually stay on the road (and get kicked up in the air) much more because it isn't being washed down the drain. Let me tell you, that filter is BLACK at 2k miles, while the paper filters I was using (OEM) were barely showing signs of being dirty. There is zero performance gain; I just have a long-term goal of making this engine last 100,000 miles.
Anyway, the stuff I used is called PureTronics electrical contact cleaner. The main ingredients are Xylene, ethanol and propane. I removed the MAF assembly and wiped it down with a slightly damp microfiber rag (dust had made it past the O-ring, gotta love living in Arizona). One quick shot of the cleaner and the little orange bulb of the IAT was clean as a whistle, but I *very gently* wiped it with the microfiber cloth to be certain. I then angled the housing over the sink and gave the MAF sensors themselves (two tiny wires that look like diodes) a big long shot of the cleaner, letting the excess run out of the "tunnel." I didn't see a big difference, but considering how well the stuff cleaned up the IAT, I'm certain that the MAF is now clean.
I let it sit for about 10 minutes so the last of the ethanol would evaporate, and then I reinstalled it, appling a tiny bit of silicon lube to the O-ring just for kicks. I've driven it for about 60 miles since then with no CEL and no major changes in car behavior, so it probably wasn't that dirty in the first place.
BTW, I've been using an oiled filter (Perrin foam) for about 14,000 miles, and I didn't see anything that looked like oil on the MAF itself, nor did I find any oil inside the airbox on the post-filter side or inside the actual intake. I re-oil the filter every 2,000 miles or so, but I am always very careful to blot the filter and massage the oil deep into the pockets of the foam. The reason I went with an oiled filter was because I live in Phoenix, AZ -- not only is it incredibly dusty here, we also have poor air quality (microparticulate count) 3 months out of the year. Also, because we get rain so rarely, brake dust and car exhaust actually stay on the road (and get kicked up in the air) much more because it isn't being washed down the drain. Let me tell you, that filter is BLACK at 2k miles, while the paper filters I was using (OEM) were barely showing signs of being dirty. There is zero performance gain; I just have a long-term goal of making this engine last 100,000 miles.