Fixed - Mass Airflow Sensor Question

Hey guys. My check engine light came on and it read P0171 when I checked it. I took it to AAA to get it worked on because I didn't have the time due to school. They stated that the Mass Airflow Sensor was faulty and quoted me $660 to change it. The cost breakdown was $355 for the part, $100 for the diagnostic, and $205 for labor. I was under the impression that this was a relatively easy fix, and when I looked on RockAuto the MAF sensor was only around $80. Am I missing something important here in terms of how difficult this process is, or is this highway robbery?

Thanks!

 

Changing the MAF is easy on a 2004. Unplug it, remove a few screws, extract. Install is reverse.

Here are a couple of posts I created (one when I was chasing the P0171 code) that show the general difficulty (ease).

https://adventuretaco.com/tag/maf-sensor/

 

Definitely robbery. Wow. That is insane.

If you do it yourself, I would just bite the bullet and pay for an OEM toyota sensor. 1st gen just does not play nice with aftermarket sensors. Also be sure to not jostle it around when installing. That filament is very fragile.

Since you did not specify engine size, I'm including removal, testing and install steps for both 4 and 6 cyl engines. Also including a YT vid on cleaning at the end of this post.

Removal for a 6cyl:


Install for a 6cyl:


Removal for a 4cyl:


Install on a 4cyl:


If you want to make sure, here is the test process for both 6 and 4 cyl MAFs:

6cyl:


4cyl:


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EDIT - You can try to clean it but again, it's very easy to damage so *be careful*.

https://youtu.be/h8RJ4cDwnV0?feature=shared

 

Diagnostic is worth it if you aren't familiar with doing that. The maf is easy, it's two Phillips screws and it doesn't need to be adjusted or aligned.

 

perhaps it just needs a good cleaning

how did this place diagnostic it exactly
did they do this here for 100$?

 

Replace those cheap JIS screws on the MAF with Allen head screws, and add a dab of antisieze

 

The P0171 code is for system too lean bank 1 which could very well be a dirty/bad MAF. It could also be a vaccum leak or a fuel pump not up to pressure. If you do replace the MAF get it from the dealer that way you know it is a factory part. Online retailers may claim it is a Toyota factory part but the price difference makes me think it is not.

 

Check your old MAF first, what exactly is wrong with it? Maybe just dirty

 

100$ diagnostic says it needs replaced

i am not a mechanic...just a hack

 

Did the michanic actually remove the MAF?
Check the screws for evidence

 

DIY with a Denso sensor from Rock Auto.

I would disconnect neg battery terminal first, then remove the MAF sensor. Be careful as the screws are very easy to strip. So apply plenty of pressure before trying to loosen the screws.

 

That probably cost u another 100$ diagnostic!

 

Same thing happened to me. Get another quote or just clean the MAF like I did (follow the Youtube video - it's easy as long as the screws aren't stripped like they were for me). If you do replace it, get the OEM MAF as others have said.

 

I cleaned it and checked to make sure it didn’t need replacing. Engine light is back on. I do have this sheet of diagnostics I got from the emissions tester at my job and I don’t know if it means anything. Anyone know if any of this will help me?

 

Is my input a take it to the bank diagnosis, no, but it appears to me that your MAF is over reporting air flow. The rule of thumb is 1 gram of air per second. 1 g/sec. Assuming she is a 3.4 so 3.2 to 3.6 is "acceptable". If she is a 4 cylinder then you are WAY off. Looking at the fuel trims and other readings, they are spot on.

This is one of those diagnosis's that techs just hate, It is bad, kind of, not bad enough to make a call but just bad enough to pop a code. If it was in my stall I would say put a MAF in it "just to compare". You can spend a lot of time and $ diagnosing, the part is more expensive than the labor. If you choose to put a MAF in it, get it from the dealer even though Amazon and EBay say factory part, most of the time they are counterfit.

 

Could I get it off of RockAuto?

 

You could just try cleaning it first before replacing it.

 

I have. Engine light is back on

 

bongo
was it 33 degrees outside when that test sheet done?

 

No, it’s currently 70F, 21C. Engine wasn’t “hot” as it had sat for about 40 minutes but I thought maybe it was the engine bay temperature in Celsius?