Hello, I wanted to clean my mass air flow sensor. Went too long changing air filter and I'm sure it is dirty now. It did throw a code and I put it on a computer and was recommended to clean it by the mechanic at the lexus dealer and they wanted to charge $300 to do so! I've done it before on other cars and it is very easy to do with MAF cleaner. It literally takes 5 minutes. However when I tried to locate the sensor on my 2010 rx450H, I found that is buried behind the air filter box with no way to access it aside from taking a lot of things apart. I even tried removing the air ducts and hoses and almost got the air filter box out but it still wouldn't pull out because it is so tight in there. Am I missing something? Does anyone know an easy way to do it? IT seems ridiculous that they would bury such a common part with no way to access it when on every other car it is easily accessible.

 

With only 44,400 miles on my wife's 2015 RX350 at the present time, I had not looked for the mass air flow sensor location until your post made me curious. Just now went outside and found it and you are correct, it is ridiculously buried underneath the windshield cowl on the passenger side with no working space to get a screwdriver in there. I would guess that in order to get to it, either the windshield cowl has to come off or the entire throttle body must be removed. So for those of you who have already cleaned or replaced your mass air flow sensor, exactly how did you get to it in order to do so?

 

You may have other reasons to clean the MAF, but an air filter that has not been replaced should not be the reason. As the filter gets old it ends up trapping more junk and ends up reducing the flow. The more junk layered on top makes the filtration better [not not the flow] so it starts trapping finer particles. Now if you have a rip or bad seal then yes the unfiltered air will start coming in and get inside the MAF path and innards of the engine.

I have not done the cleaning so I can't comment on the procedure.

Salim

 

then this would, by default, make the throttle body cleaning very difficult.....

 

Sounds like the Lexus dealer mechanic needed to meet his monthly sales quota. Just pour a bottle of Techron fuel system cleaner in the gas and call it a job well done. I doubt your MAF needs cleaning. Do you have any driveability problems? Bad Idle? Roughness? I doubt it.

 

I cleaned by the maf on our 2010 rx350 earlier this year when I changed the spark plugs since the windshield wiper cowl was off. At the time I didn't see how to get to the screws to remove the maf with the cowl on. I ran into the same issue about removing the air box and hoses (couldn't get the section holding the maf sensor without violating a gasket of some sort iirc)

 

Thanks for your information. Looks like windshield cowl removal is indeed the best way to gain full access to the MAF sensor. What a moronic design....

By the way, did you have to remove the intake manifold to change the spark plugs, or was removing the windshield cowl enough to get to all of them?

 

For spark plugs, I did not remove intake manifold. Yes it was pita, but I don't get along with large gaskets.

 

Thanks. Glad to hear that the spark plug job can indeed be done that way.

 

AM I SAFE USING THE 'CRC'- Mass Air Flow Sensor cleaner on this vehicle ?

 

That is what I have been using for years to clean the throttle bodies on all of our vehicles. Multiple light coats are better than one big gloppy coat.

 

The rx450 might be slightly different, but for our 2010 350, I just attempted to recleaned the maf by removing the rubber air duct that goes from the maf housing to the throttle body. There's One vacuum hose to disconnect from that rubber tube and then another hose that clips onto that duct just to move it out of the way. The maf can then be accessed and I used maf cleaner with the straw to direct the spray. The part that may not be completely cleaned in this manner is the wire that's deep in the maf housing. Gotta make sure you disconnect the electrical connector first if you attempt this cheat (without removing the actual maf by removing the cowel. ) Ymmv. For those that are curious, the reason I re-cleaned it is because my fuel trims were getting a little high positive. It did help. It's been 50,000 miles since I cleaned it previously when changing out the spark plugs.

 

Thanks rx in nc

 

Watch the below video BEFORE attempting cleaning your Lexus's MAF sensor, which is VERY delicate sensor.

 

I would not risk cleaning the MAF sensor. It is one of those projects that may end up causing more harm than good.