Mass Air Flow Sensor


harkauto
03-14-2014, 08:58 PM
I tried a search for my particular situation but can't seem to locate what I am looking for. Could be I'm not using the correct description.

I read an article on line that said on high mileage cars a person should replace or clean their Air Mass Flow Sensor to assure a smooth running efficient automobile.

I have a 1999 4 cylinder Toyota Camry LE that has just turned over 150,000 miles and even though it runs beautifully and seems to get great fuel mileage I want to clean and maintain this part. Problem is I can't seem to locate this part under the hood anywhere. Someone told me that my 4 Cyl does not have a MAF but instead has a MAP.

My questions are what is it that I actually do have MAF or MAP....where is it located....and is it a part that can easilly be removed and cleaned with the aerosol Mass Air Flow cleaner?

Thanks for your advice!

Harkauto:confused:

Brian R.
03-14-2014, 10:42 PM
You have a MAP sensor, no MAF sensor. They operate on totally different principles. The MAF sensor has a wire which is cooled by incoming air flow and tells the ECM how much air is coming through the intake. The MAP sensor is a pressure sensor and has no wire to clean. For further details, see the following article:

http://www.autoshop101.com/forms/h24.pdf

The MAP sensor is located in your intake plenum and it shouldn't be cleaned.

harkauto
03-15-2014, 09:05 PM
You have a MAP sensor, no MAF sensor. They operate on totally different principles. The MAF sensor has a wire which is cooled by incoming air flow and tells the ECM how much air is coming through the intake. The MAP sensor is a pressure sensor and has no wire to clean. For further details, see the following article:

http://www.autoshop101.com/forms/h24.pdf

The MAP sensor is located in your intake plenum and it shouldn't be cleaned.

Thanks Brian for the valuable information.
Do you think I am safe in assuming concerning the Map Sensor and the Oxygen sensor in my 99 Camry that if the car runs fine, the engine idle is smooth, the fuel mileage is good, and there are no code lights lighting up on the dash.....to just leave well enough alone and drive the car?
In fact....in the event one of these devices goes bad, or is on its way out....will I probably get advance notice in the form of a warning light on the dash?
I guess I'm probably a little paranoid as a result of reading articles on line that suggest I just go ahead and replace these items on the car especially if the car has over 100,000 miles on it.
If these were inexpensive parts it would be no big deal. But I hate to prematurely throw a lot of money away if not necessary.

Brian R.
03-16-2014, 02:17 AM
If it ain't broke, don't fix it.

harkauto
03-16-2014, 04:32 PM
If it ain't broke, don't fix it.

Probably some of the best advice on the forum. I know other guys who in their paranoia replace stuff on their cars simply because someone else had a problem with the same items on their car.
I wonder how much is spent needlessly.

Brian R.
03-17-2014, 04:10 PM
Not only that, on any older car, there is a very good likelyhood of damaging a piece of plastic, or stripping the threads on a fastener, that will cause much anguish since it is attached to an expensive part, part of a critical wiring harness, or very difficult to get to, and necessary.

The less work done on older cars, the better. You almost never get away unscathed when you replace one of the original parts.

(the above is also a very good reason why you should, whenever possible, work on your car yourself. Many so-called mechanics will do one of the above and not tell you about it.)

harkauto
03-17-2014, 04:53 PM
Not only that, on any older car, there is a very good likelyhood of damaging a piece of plastic, or stripping the threads on a fastener, that will cause much anguish since it is attached to an expensive part, part of a critical wiring harness, or very difficult to get to, and necessary.

The less work done on older cars, the better. You almost never get away unscathed when you replace one of the original parts.

(the above is also a very good reason why you should, whenever possible, work on your car yourself. Many so-called mechanics will do one of the above and not tell you about it.)

ABSOLUTELY! Unless it is something very very major in which I have absolutely no expertise whatsoever...I ALWAYS do my own work. Even with semi-major issues I will research an issue to death in order to determine if it is something I think I can tackle. I do this concerning my cars, my home, or anything else that needs to be worked on and have saved thousands of dollars over the years as a result. Plus luckilly I have NEVER had an experience where I thought afterwards that I should have hired it done.
Nobody cares about your stuff more than you do and we have all heard horror stories about how the so-called experts screwed something up, or broke or damaged something else in the process.
Also, could be cynicism or old age....but I just don't trust anybody anymore to even touch my stuff.
Case in point....I took my car to a tire dealer the other day to have my free tire rotation done. The mechanic came to me and said one tire had a screw in it and needed to be replaced at the tune of a couple of hundred bucks. He walked me to the counter and I could tell he thought he had a pidgeon for a customer and I quite caught him off guard by asking to see the tire; so we walked out back and I totally expected to see a tire with a gigantic screw protruding through the sidewall of the tire or something similar. When we arrived at the tire he pointed to a tiny screw head protruding from near dead center of the face of the tire. I could tell from the size of the screw head that the threaded shaft of the screw could not be more than 3/16 of an inch in diameter. The screw was so small that I had not even noticed any air loss in the tire.
I looked at the mechanic and said....."So what's the big deal with this?"...."Just plug and patch the tire". "Simple!".
The mechanic said with a very serious tone in his voice....."Ohhhhh I would not trust or put my faith in that tire if we did that!" I told the mechanic....."look these are 75,000 mile tires....the best they make, and they still have 80% of their tread on them and are only two and a half years old....just plug and patch the tire!
The guy thought I was some kind of moron or something. I have pulled tires off of cars that were near bald and found plugs and patches on the inside that were still sound and holding air.
What makes me made is that if my wife had taken the car in she would have ended up spending a couple hundred bucks needlessly.
I imagine they are always ripping off women and men that don't know any better.

bigrick7
04-01-2014, 08:32 PM
i think what you want to clean is the air flow idle valve. which is located in the throttle body. remove air intake hose to throttle body look inside throttle body there is a rectangular opening spray that with injector cleaner while revving engine to prevent engine from shutting off. but if the car has smooth idle no need to clean this part.

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