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Not sure how to post this thread but I would think everyone interested. 2012 Mazda 3 with 2.0 Skyactive. Out of the blue one day (40k miles), when I cranked the engine over it would start and run for maybe 5 seconds then die. Never got past the normal warmup high idle cycle that the Skyactive has programmed at startup (multiple attempts). Got a P0101 code on the scanner eventually which is for Mass Flow Sensor (MAF) problems. Cleaned the MAF per requirements and found that the unit when cleaned still killed the engine in 5 seconds or less (no fix), but if disconnected at the plug would run at almost 85% but a little rough. Good news for me.

Replaced MAF with new OEM unit from dealer ($230) and the problem was solved (two screws and two minutes, then reset ECU. Fixed....but bummed my almost new car is having issues already.

There are some good threads for testing MAF sensors with volt meter which I never got around to doing, but interested in for next time.
 

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is the MAF not covered under the 5/60k warranty? Im going to be pissed if my maf dies when the car is two years old and have to pay for it out of pocket
 

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is the MAF not covered under the 5/60k warranty? Im going to be pissed if my maf dies when the car is two years old and have to pay for it out of pocket
Yea I run a hot air/debris intake as well so I clean my maf with the spray when I clean my filter. I also cleaned my spark plugs with gas at 30k since the engine will run a little richer (and dirtier) from the SRI. That being said I haven't had any engine problems other than those arising from bad tune files (temporary problems).
 

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is the MAF not covered under the 5/60k warranty? Im going to be pissed if my maf dies when the car is two years old and have to pay for it out of pocket
Have a limited 3 yr or 36k mile warranty. Bummer for me. Didn't think something would happen so soon. If it happens again I will look at aftermarket replacement to see how they perform. They are easy to replace.
 

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Have a limited 3 yr or 36k mile warranty. Bummer for me. Didn't think something would happen so soon. If it happens again I will look at aftermarket replacement to see how they perform. They are easy to replace.
yeah everyone has a 3/36 for the basic warranty that covers like paint, seats, and cosmetic stuff everyone should have a 5/60k for drivetrain. They didnt tell me that at the dealer either but according to the book it does indeed have 5/60 for drivetrain. The way I see it if the maf is keeping the car from running seems like a drivetrain issue to me but I know warranties make some distinctions and call items wear items.
 

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No way an OEM MAF sensor should kick the can that early. My previous car's factory MAF went for 18 years and 150K+ and that's with using a K&N panel then switching over to a short ram later on. As for aftermarket MAF units, I wouldn't bother. OEM or OE all the way on sensors.
 

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Replaced MAF sensor 2012 3i 2L Skyactive

Just replaced MAF sensor on 2012 3i 2L Skyactive. Only 50,000 miles. Old Sensor looked brand new so thot it was going to be something else. Wasted $10 on the CRC cleaner. No Help. Spent $200 for new Denso Sensor at dealer. Symptoms were Chk Eng Lite, Power Steer Lite, OBD codes displayed for the sensor & also said Too Rich (Bank One) Car would start and rev then immediatly die. Engine ran (bad) with sensor unplugged so decided to buy new sensor and now works perfect. Could have got Denso Part online for mabe $120. SO - can't tell by looking at electrical parts! I would have bet $20 old sensor was just fine but I was wrong.
 

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Do any of you guys use k&n or similar "oiled" aftermarket air filters? if so you have to be extremely careful when cleaning and reoiling them not to get too much oil on the filter and let it dry complete before reinstalling. the oil for the filter will ruin a MAF sensor due to coating the wires with oil and then when the MAF heats the wire it burns it in to it and bam sensors bad. The instructions from k&n on re oiling say let it wick for 20+ minutes I go much much longer then this 3 hours minimum and usually try to do the cleaning in the evening or right before bed(when I know I wont have to use the car that night again) and re oil and let it sit on a few layers thick of paper towels over night to ensure its dry 100% in the morning then reinstall. MAF cleaner is a worthwhile thing to do but will not solve a faulty sensor. I also use maf cleaner and clean the intake and filter box as well as the MAF sensor at this same time.

if you don't use performance type filters like this but use stock paper ones make sure they are changed every 10-15k miles or at least annually if you drive less then this amount a year (even if the manual says longer, trust me most places especially in cities with road work get so much dust and crap sucked in that they get over full before 24-30k interval in the manual) this prevents the filter from becoming clogged and letting tiny dust particles by as it cannot hold anymore and has to release some its holding to hold new ones (the air is forcing them out) these particles then flow into the intake and hit the MAF sensor, well a maf sensor works by heating a razor thin wire really hot and then senses air density and temp by how much the air coming by cools this wire off, the wire gets extremely hot, its almost like a halogen light filament, well this melts these particles onto the wire and after too much builds up cleaner wont get them off and the sensor cannot sense any difference in air as it heats the wire so then it throws the CEL on and pus the car into a predefined fuel map and you get worse performance and mpg or even hard or no starts because the MAF sensor is the main sensor the computer talks to. they communicate air volume,density and temp by 1s and 0s changing constantly same with 02 sensors in the exhaust, in fact o2 sensors and maf senors work very similarly. the only way to be sure your maf sensor is bad is to change it, if you don't have a medium-high dollar scan tool that can do live data and see the maf readings, but you would also need the specs for normal operation under the test conditions to determine anything with this. or a voltmeter that can read 10,000+ ohms and have the specs for resistance under test conditions for a normal working sensor so you can determine if it is out of spec and bad
 

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You are awesome! Out of the blue my (out of warrantee) 2013 mazda3 w/36024 wouldn't stay started. Seemed like a fuel related issue. Saw your post and unplugged the MAF and bingo - started right up. Bought a new OEM on Amazon for $140 and fixed it. Thanks so much!!!!
 
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