Codes PO140 and PO171, what are these telling me?

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2015 Mazda3
Each time I'm at a stop, the car sounds and feels like accelerating. A week after, the check engine light came on with those 2 codes. Also, the car would not start at one time but I kept trying to turn it on, and it started finally.
 
P0140 could be bad O2 sensor bank 1 sensor 2 which is the sensor after the catalytic converter.

A dirty MAFS (mass air flow sensor) could cause the the issue so try cleaning it first before replacing the O2 sensor.


P0171 could be many things, the most likely cause being a dirty or faulty MAFS sensor


Try removing and cleaning the MAFS sensor first, its easy to do - if you do not know how you can google it or look on youtube for a tutorial
 
I will. I do have the maf cleaning spray that I used for my old car.

The car is a 2015 Mazda 3 isport with 156k miles on it. For a newer car I find it strange that the O2 sensors would go bad that quick!
 
I will. I do have the maf cleaning spray that I used for my old car.

The car is a 2015 Mazda 3 isport with 156k miles on it. For a newer car I find it strange that the O2 sensors would go bad that quick!
 
Great, now PO300 has just popped up. I was told this is regarding spark plugs needs to be replaced ��
 
Maybe it's time to replace all 4 ignition coils too since it's already 155K miles? I've never replaced it ever.
 
The maf sensor is the idle air control valve or not?

Where would the IAC valve for my 2015 mazda 3 be located?

P0140 could be bad O2 sensor bank 1 sensor 2 which is the sensor after the catalytic converter.

A dirty MAFS (mass air flow sensor) could cause the the issue so try cleaning it first before replacing the O2 sensor.


P0171 could be many things, the most likely cause being a dirty or faulty MAFS sensor


Try removing and cleaning the MAFS sensor first, its easy to do - if you do not know how you can google it or look on youtube for a tutorial
 
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