MAF Sensor replacement (numerous times)

Can you go into some detail as to why you're replacing it?

 

If I needed one, and had an older vehicle, my first search would be one of those junk yards with the pick-and-pull. Many have good customer service and can look up vehicles either on-line or with a phone call. You just bring your tools, remove the parts you want, and go inside to pay...usually at very reasonable prices.

For a 2009. Part Number should be 22204-22010. MSRP is $170.35 and Sparks Toyota online sells for $114.71. Overseas, Amayama has them for $90.03 and you pay shipping which is usually not too bad.

 

Yes I have about 10 in my toolbox storage bin I pull them out of Gen 2 and 3's all the time All the sensors I can get when they come in and I see them just to have them I am not paying $200 for an MAF sensor cheap Chinese junk is $12 and believe it or not many times they work not very long but they work It seems like there's not very much to making an MAF sensor a reasonable company could make one for near nothing and have it work but there's no money in that so they can sell millions of them at 10 $12 and only $400,000 work oh well and that's the thing that bothers me the most there's no way I could put my name on a company that was doing something like that just out of the sake of my name or whatever I mean that's just pure stupid it seems like seems like some companies spend as much money doing things the wrong way as what it would cost to do it the right way and make money and have a good reputation It just seems mind boggling.

 

I replaced daughters maf sensor, thought codes meant replace it. Codes don’t mean that. The problem was cracked air hoses going from throttle body to air cleaner and maf. Both had cracks in the bottom from age. At the time densoproducts had a maf for $75. Still was wasted money. 2002 Camry.
The air leaks upset the maf readings and the codes were set. Nothing wrong with 02 or maf. Car ran so well after new hoses. The large duct hoses like bellows. So assume for now those new mafs are ok and probably the original is too and keep looking. One is air or vacuum leaks in the intake. It is not the maf are all bad.
The 2007 Prius takes the exact same Denso part number maf as the 02 Camry. The dealer might sell the screws, or a hardware store.

 

buy a Denso off Amazon, stop buying those shitty autozone parts.

 

Just about sprayed my drink all over my computer from laughing so hard. This could be the funniest thing I've read in weeks!!

Just hope and pray you chose the 5% that's genuine, lol.

 

That's why just reading the codes is only a first step. It's just as important to look up what the codes mean, using a reliable source, like the repair manual for the car.

Toyota Service Information and Where To Find It

That's where you learn that P3190 only tells you that the engine is running poorly (producing less than a fifth of the expected torque). P3191 means the same thing as P3190 except it happened while the car was trying to start the engine.

Both of those codes are set by the engine control module (ECM) itself. P0A0F comes from a different ECU in the car, the Hybrid Vehicle Control ECU, which is more like the car's orchestra conductor. P0A0F simply means "hey, I cued the ECM to give me such-and-such amount of engine power and it didn't happen, go ask the ECM about that."

So a P3190 or P3191 just means you need to go diagnose why the engine is running so poorly, checking all the reasons an experienced mechanic would check on a gasoline engine running poorly. Then, once you've found what the cause is, you fix that.

If you skip doing that and just jump to replacing some part (whatever part you happen to pick) and that doesn't solve the problem, that just means the real cause is one of the many other things you didn't check.

 

That’s what I was talking about, learned a lesson with wasting money throwing parts at a car. I try to learn and not get caught in a rut of thinking. Looks like others may want the op to keep on wasting money, and not realize it is highly likely something else. Autozone gets back perfectly good parts which are claimed to be faulty. I am pretty sure these are returned to the vendor, maybe thrown away. Raises the prices of parts. I think I still have the perfectly good maf sensor which was the original on a 2002 Camry. Added air, after the maf read the air, totally fouled up the maf data to the ecu. Nothing wrong with maf sensor at all.
Also go to the service manual, Toyota gives step by step tests to check a sensor. Look it up on the internet, or spend the $25 for a two day service manual access. Follow their instructions, likely lead to the problem.

 

Sorry if it sounded like not giving you credit, but what we guys were saying was basically "to go diagnose why the engine is running so poorly, checking all the reasons an experienced mechanic would check on a gasoline engine running poorly. Then, once you've found what the cause is, you fix that."

But all I could see in the first post (it's in the thread title too) was that you'd replaced the MAF sensor (numerous times).

Maybe all of what we were saying was done already, and that was how you ended up at the MAF sensor. But unless you fill us in on just what was done already and how, it's hard for us to see what might have been missed.

 

It took people time to help, a lot actually. How is anyone supposed to know what you already did, except change the sensor over and over like you said. I told you about the intake hoses, you didn’t say you checked those in the posts. So for me, another learning experience.

 

Buy parts like that from rockauto.com or a dealer.

 

Does the Prius intake system have a bellows area? That section has failed on the intakes of several of my previous cars. Invariably it tears open on the bottom and you can't see it unless you look with a mirror or take the thing off so that it can be turned over.

When we got my wife's Accord from her parents 10 years ago we had a shop change every single rubber hose in the engine compartment and all the belts (the car was 15 years old at the time). I believe they changed the rubber part of the intake with the bellows then too, but in any case when the most recent starter failed (Accords tend to eat these) we pulled that tube off for better access, and the bellows was shot, as usual, on the bottom. Failed in less than 10 years (probably), but it might have been the original, in which case it was < 25 years.

 

The Camry bellows’s get bent from air filter changing or other work and it stresses them. I searched for a month doing all sorts of things then out of wanting to try something different I checked the bellows tubes. It was like a new car. I don’t remember what a gen 2 has. I don’t think it is all plastic and steel.

 

I google'd for pictures of the air intake hose, and the hose immediately downstream from the air filter does have a bellows section. That would be after the MAF, so a leak there would let in air the MAF didn't take into account.

Hmm, wait a minute, maybe that is upstream? I don't recall if the air goes right to left or left to right (facing it from the front of the car) across the filter. Here is a diagram:

Engine Air Intake Hose | Part #1775121120 | Toyota Auto Parts

 

Air enters the filter box through the tube with the bellows, and exits straight down past the MAF sensor in that direct stubby connection to the throttle body.

It is good to see diagrams working on autoparts.toyota. It was seeming as if they had broken that site for good.

Ah, but wait, they're still diagrams you only see after selecting a part, right?