http://autotechrepair.suite101.com/a...r_flow_sensors
Do we really clean the MAFs on our car? Or is it really just the throttle body? I mean, the MAF is really just an expensive electrical component, right?

 

I am talking from 928 experiance here.....

But you woudl be shocked at the amount of crap you get out of a MAF. CRC makes a MAF cleaner.

If it is dirty, it does make an improvment you can feel

 

Haven't driven my 996 (Turbo) that much yet, just 20K miles, to have much experience but I drove my Boxster almost 80K miles before a failing AOS (though I didn't know it at the time) caused me in an attempt to "fix" the symptoms clean the MAF. I cleaned it over some clean papers and the thing just wasn't dirty.

I did clean the throttle body cause it was oily in fact had a drop of oil hanging down on butterfly valve. This "normal" from failing AOS -- I figured out later -- cause so much oil and oil vapor routed to intake just behind TB that some of this can help but get on the TB.

Also, an engine overfilled with oil could result in an oily TB.

It would be a stretch to believe that an engine overfilled oil could foul the MAF given the MAF is so far from the connector where the AOS hose connects but if engine overfilled with oil and acting up after lowering oil level to the proper level then cleaning the MAF and TB could be called for.

If the engine air filter is compromised this can allow a great deal of dust in and this dust could foul the MAF. These engines use a hot film style of MAF though and one benefit from this style is better immunity from being affected by dust. (Unlike hot wire MAF which has a wire cleaning cycle that heats the wire to red hot to burn away any dust or dirt on the wire.)

I'm now over 228K miles on my Boxster and have cleaned the MAF just once, no make that twice, the 2nd time when due to some error codes I suspected the original MAF going bad and while I had it out to look at it decided to clean it. This around 150K miles and again MAF was not dirty. I never bothered to look at the TB. Based on the error codes I did replace the MAF which didn't fix the problem. Turned out to be a leaking oil filler tube cap.

In fact, some time later, scores of thousands of miles later, the 2nd MAF did fail -- I verified this with greater care this time -- and on a hunch installed the original MAF and this did fix the problem. And the old original MAF is still working just fine now at 228K miles.

At I forget what mileage, 2nd AOS failed and MAF and TB not even cleaned then.

You can clean the MAF if you want. As long as you take care -- it is a rather delicate and very expensive item -- and the TB too whenever you want, but based on my experience with a stock engine with no AOS problem, stock air filter, and a properly installed air filter, neither the MAF or TB get dirty enough to bother taking the time to clean either.

Sincerely,

Macster.