So my engine was dieing randomly at stop lights, rough idle, jerking around, all intermittent, no check engine light, blah blah blah, all the tell tale signs of a bad MAF. EGR & IACV & TB have been cleaned, oil changed on the regular, always with additives, only use premium gas, also use fuel additives occasionally, new spark plugs, no problems with intake, exhaust, so on. Even took it to a mechanic for a second opinion, their machines isolated no fuel related problems or air related problems, so he agreed: MAF.

So I do a quick online search, buy one up, and replaced it. And it doesn't die anymore. And it idles great. And gas doesn't shoot through the engine like fast food through my gullet.

But one day later, I get THREE engine codes. P0171&P0174 which is bank1 and bank2 lean, and P0446 which is some EVAP nonsense. wha wha whaaaat? I was running rich as hell 2 days ago, and now I'm LEAN? nahhhh.

I do the voltage measurement thing on the new MAF. I re-install the original MAF and do the voltage measurement again. Basically same results on both: in spec for 99% of it, but randomly blips down way out of spec (like 0.2V). Could be normal, could be the problem, I considered the test inconclusive honestly. So I do MORE research on here and find a few suggestions of how incredibly important a genuine Nissan MAF is. Cuz, yea, I bought a new one off ebay for $50.
http://www.ebay.com/itm/170666635578...84.m1497.l2649

Are these codes just my car's knee jerk response to new info? It's still driving sluggish. Or is my $50 no-name MAF totally my problem and this is one part that it's "go factory or go to hell" ? They claim no returns on installed parts so I'm hoping I'm ignoring something.

Oh, and upon research of the P0446, I find out about that valve behind the driver rear tire. Took that out, thing moved freely, cleaned it anyways, reinstalled. So that was not an issue to begin (or end) with.

 

See below:

 

Probably a bad reman. It happens all the time. I would get reman nissan. They fail too but buying from the dealer is waaaaay to expensive. Look in the classifieds or find one on ebay and ensure it is real as much as you can and double check the return policy

 

Sweet, thanks for the responses guys. After I put the original MAF back in place (to get ready to ship back the new no-name one), it started driving like garbage again. So since they were playing a long delaying game on the return policy, I figured, what the hell, I'll run the other one until they would take it back. And after just a day or so of ridin on the cheapy MAF, things got nice and smooth and worked out their own kinks with no CELs. I don't get it. And I'm not questioning it. When this one goes bad, I will def get a reman Nissan genuine one. Until then though, I gotta say, this $50 MAF is actually working just fine after the initial hiccup. And since I have MAF cleaner, I'm just gonna regularly spray her down just for fun. Thanks again guys for the input!

 

Sounds to me like it was having difficulties adjusting from bad maf to good maf. Did you do an ecu reset after replacing the maf?

Not directing this at you, per say, but it amazes me how few people realize that when you change certain electrical sensors, you need to reboot the ecu. Since the comp had to learn how to function with a bad part, simply replacing the part isn't enough. Without performing a reset, the car is forced to relearn in-progress.