MAF sensor question - 2000 Maxima

This question is for someone who has dealt with this problem before.

my brother ruined my MAF by accidently spraying oil on it to clean it, so i bought a used one from ebay. the used one was installed, but it still dies right after starting & will not revv. do USED maf`s need to be programmed in like the new MAF`s??? :frown:
thanks for your help.

...MAF by accidently spraying oil on it ...

- oil will NOT ruin it. Take the shielding grids out, use electronics cleaner, brush...
- Try running without MAF. Should run 'ok' but wobble a bit, 2.2k rpm ceiling.
- After MAF swap or cleanup ECU has to be reset as all sensors are 'individuals'.

- ECU Reset = batt cable out for 30min; this clears ECU O2/MAF/Injection-related memory. It will start from factory settings and compile data. This continues until injection is adjusted so that O2 sensor feedback is in line with new MAF input.
- read MAF related links from this page http://www.cardomain.com/ride/748507/9

hi,
i followed your advice & cleaned the used replacement sensor with electrical cleaner, and after leaving the battery unhooked for 45 min, it started with no check engine light on, but as soon as i revved it , it came back on & wouldn`t rev past 2200 again.
so i disconnected the MAF & battery again and am letting it sit again. So, do i need to let it idle for a certain amount of time to let it relearn, or something?? is there something i`m doing wrong???

I`m about ready to bring it to the dealer, but it ran so good before this happened ,and i DO NOT trust the dealer.
thanks for your help.

...cleaned the used replacement sensor ....

Clean your oily original and try that.

MAF has a learning period compensating between O2 feedback. If I remember right, its some 20 minutes with special phases in driving style, however, just drive ... takes little bit longer. NO rpm ceiling at all, works real well from the beginning. (all explained via downloads - see the link page 26)

The rpm ceiling is when MAF (or some other) sensors fail totally. One may measure the output voltage with dmm, it has to rise as airflow rises.

You may now have two dead MAF's, it would not be first such case. From what you write, your problem is in the MAF or its connection. Stealership cant change that situation but by installing a new MAF - theyll be happy a$ a banker to do $o.

Self diagnostics also will show the error code for MAF. Some dealerships, autozone, may do that test for free when asked... -OR- try http://www.scangauge.com/ ... Ppl tell this is a nice info tool. Easy to install, always realtime info. Fits -95 Maximas or later, all OBD-II. Helps you to be on top of rep air$hop swapping games. ... I have no experience, but I will if/when I own a OBD-II -vehicle

My guess: Its only 10% to buy third used MAF (and hope it works) than visit the stealership and pay for whatever they wish. Dont get weary as here the symptoms fit the probable cause perfectly - losing faith is costly.

yeah, that IS the only thing that makes sense too, that this sensor also is bad. only problem is that i stupidly tossed the old one in the trash days ago & it`s gone now.
good luck to the dealer to try to sell me a new one. i can get a BRAND NEW one on ebay for 112.00 shipped, which is probably my next move.

thanks so much for your help. i`ll post an update when i have more news.

...i can get a BRAND NEW one on ebay for 112.00 shipped, which is probably my next move...

Its good to have a resource like that, hope it works. I would probably just lose my 112$ receiving a brick...?

Where do these cheap sensors arrive? One source is 'shop swappers' who charge unaware customer for nothin -and- swap the part into ebay.

okay, so the dealer called & said it DOES need a new MAF, surprise!! right??? he wanted 331 for a new one installed total, but i told him i dont have the money to wrap it up & i`ll come get my car as is.
so i`ll wait & get the new one off of ebay now ,like i said.

Just to make sure i understand you perfectly...... you said i won`t have to bring it back to them after replacement for them to "relearn" it on the computer at the dealer, right? because that`s what theyre trying to make me believe. i should just be able to reset it again & drive it on my own over 20-30 mins & it will relearn itsself??
thanks again!

Ya, just reset your ECU after you get it installed. It takes about 500 miles for your car to compleatly "Relearn" everything. Thats all they are going to do, reset it and charge you a bundle for it!

Good Luck!

... it will relearn itsself??

Its a half truth, from their perspective it$ their truth. Dont blame them, they just say as theyre designed to say (via FSM). Check the link I gave you, page 26 and download... read how it goes. A new MAF input differs always from previous - this difference has to be 'taught' to ECU with specific driving pattern. You may do the driving if u follow the guide. But as Bezer said, ECU will get all info by itself (in normal drive it takes longer to hit those 'patterns' required to fill ECU tables = each required setup condition has to be met).

MAF gives signal from current air flow. TPS how gas pedal is being used. This and some other inputs are used to decide how injection is executed. After warm up, O2 sensors will give feedback info how well the process went. Typically it didnt go perfectly (MAF signals not right etc) ... and this will be corrected. Gathering this correction info -table into ECU memory, needs to meet the specific driving situations. Teach drive -or- just drive = takes more time.

IT`S FIXED!!!! thank God!!!!!!!
I picked it up from the dealer after giving them 95.00 for diagnostics, went to Napa & got a NEW MAF sensor for $130 with tax , reset the computer, & it runs like a new car! simply amazing~!~!
THANK YOU SO MUCH for walking me thru this!!! you`re a life saver!!

IT`S FIXED!!!! thank God!!!!!!!
I picked it up from the dealer after giving them 95.00 for diagnostics, went to Napa & got a NEW MAF sensor for $130 with tax , reset the computer, & it runs like a new car! simply amazing~!~!
THANK YOU SO MUCH for walking me thru this!!! you`re a life saver!!

Actually youre here the hero: facing first time this kinda issue, ppl typically give in and pay. and pay. But yes, all honor to Him.