Symptoms of failed Mass Air Flow sensor on 2009 Prius...?

It is reasonable that a problem with the MAF sensor will cause driveability symptoms. You might ask for the tech to try cleaning the original sensor first, rather than replacing it.

Also, check the engine air filter, the dirty side is on the bottom. It should be replaced at 30K mile intervals.

 

$400 to replace the MAF sensor is malarky.

The part can be bought for $50 at Rockauto and removing/installing it is so easy a caveman could do it!!

 

The Toyota dealer is not going to buy parts from Rockauto.

MSRP of the correct Toyota part is $183, so a $400 dealer repair invoice is not impossible to comprehend.
2005 TOYOTA PRIUS Parts - Champion ToyotaWorld

I'm assuming that if the OP had the knowledge to replace the mass air flow sensor, he would not bother to post the query.

It is true though, that replacing that part will take around 5 minutes. The trick of course, is to know which part to replace and be able to remove the wiring harness connector, without causing more harm than good.

 

Haha, yes of course they wouldnt.

Guess I let my DIY mindset get the best of me. I personally wouldnt pay $400 for the Toyota Dealer to replace the MAF sensor, even if it were Jesus himself behind the wrenchset.

So the Dealer would charge $217 in labor for the MAF sensor replacement? Although the price of the MAF itself ($183) alone makes me fall out of my office chair, that labor is even more extravagant to those of us here who have removed the MAF sensor before to clean it (3 minute job).

 

Yes. I searched the site and found a few instances of it.
Can debris in the mass airflow sensor shut the car down? | PriusChat

The MAF can go bad or start complaining from bad air filtration, or not be bad but just dirty (I cleaned mine last month & at 60k miles it was dirty), it can also fail from somebody overfilling the engine oil level. The Prius is very sensitive to overfilling and oil will contaminate the MAF wires if that was the case. Some oil change places assume the Prius takes 5 quarts of oil when in fact it only takes 3.9 quarts, but is happiest at 3.5 quarts.

The more you know.....lol

 

Had the MAF go bad 1 day after i had the 2 recalls done on the prius...i thought at first the recalls had something to do with it, but it was all coincidental...anyway...2 screws later the old one was off and a new one was put on...i did it in about 10 minutes in my garage...given the car would not stay running...frankly it gave us a 2 minute warning...check engine light, then the triangle of death...i pulled the +12V and reset everything...car mileage went from 42 to 48, even with crappy winter blend gas...runs like new...

 

Did you try cleaning the old sensor? It is common for debris to get into the MAF and cause a problem, however, These MAF sensors almost never go bad. The air filter could have been inspected while the recalls were being performed causing debris to get into the MAF.

 

we cleaned the old one with MAF cleaner..and it was very dirty...reinstalled it and was able to get the car running ,however, given that we are out in the middle of the night and in the middle of nowhere 90% of the time...i just did a quick replacement...( at 90,000 miles)...held on to the old one and put it in plastic bag in the tool box just in case...looks like the air filters were alledgedly inspected which could have put some minute debris in there but we cleaned it all up ...of course the oil level was just a tad under full...where it belongs...

 

The next question you might consider is: why was the old MAF sensor so dirty? How often do you change the engine air filter and do you use the correct Toyota filter; or some aftermarket substitute or even worse, an oiled K&N filter?

 

engine filter every 8-10k miles with oem paper filter...never an oiled filter...and the oil level is always just under full...been changing oil in prii since 04 myself...never could trust dealer ...other than that i guess after 90000miles it just said (MAF) enough...ok changed out and back to normal...

 

Mine was not the maf on my 2009 prius, they told me it's somewhere down the harness connected to maf.. cause everytime whe would move it around car was messing up and pulling all these different codes.