Now getting off topic...but blackworks, do you think this:
K&N Response to Mass Air Flow Sensor Concerns
is just a bunch of hoo-ha? I'm not trying to start anything, just legitimately interested in your opinion/facts.
Well I appreciate you asking for my opinion and I will try and keep it as concise and civil as I can. I'm going to preface that I am not against K&N products, I am merely correlating my personal (and the experience of many other technicians) in regards to Oiled Filters (K&N being the most popular brand of said style.)
First off their website section that you linked is an amazingly well done piece of propaganda and false research, now I call it false research for the following reasons:
-They provide NO actual data to support their claims (there is no particulate data, no flow testing, no chemical analysis results, ect.) They only show this neat chart of "how many were good, how many were bad, what dealerships sent us stuff."
-All their videos, links, graphs, pages, ect. all have the most vague, uninformative, and over all useless information that has no bearing to support their claims (the videos and charts look nice though!)
-They're testing methods are what I would consider somewhat vague in some respects. At one point their talking about how they measure the air speed going INTO the filter. Why you would choose to show this data is little more than a red herring, I would be more interested in CFM through the filter under various vacuum loads Under Oiled/No Oil, Over Oiled, and Normally Oiled (to simulate typical vehicle conditions/owner maintenance) as well as particulate data from what non-sterile air is filtered through (Which most of that data should be easy to source since they test their filters the same way for performance!) Another example is "weighing" the possible oil transmitted through the filter on a larger filter, this again seems asinine to me (why not a spectrum analysis or even a hydrocarbon detection?)
-The pictures of failed MAFs and manufacturing defects, while valid, do not account for a large enough swath of makes & models to account for their claims of innocence. I'll even give them the benefit of the doubt and say half those MAFs are replaced because the tech/shop/dealership is "shotgun" diagnosing.
-Now I personally don't think a single instance of K&N oil getting on a MAF will kill it (okay, maybe a BMW or Chry-Crap sensor...), but repeated contamination and lack of cleaning due to an ignorant or uninformed owner (who believes K&N) could result in contamination that could lead to sensor failure (particularly on Hot-Wire style MAFs that use a heating element much like a O2 or AFR sensor do.) Again this comes back to their testing, they fail to mention how much of the MAF sensor they are testing. Modern MAF sensors actually typically have the MAF portion, IAT, and a Heating Element built into one unit; any of these failing/not reading correctly can cause issues.
-They list sources and "Independant Testing" yet cite neither of these to verify they actually had another company review their findings. None of their findings have any evidence of peer-review (granted they're not saying they found the Higgs-Boson, but you want me to believe you would test and admit you have a horrible issue with your product?)
I think that's enough poking holes in their very nice advertisement page.
From my experience (and the experience of many other technicians) what I have seen K&N/Oiled Filters do is almost opposite of what K&N says.
With Toyota, I have noticed even using dry media OEM (not performance or "high flow" like AEM, Volant, ect.) filters the MAF sensors stay relatively clean as along as the filters are changed at a somewhat less than acceptable interval (think the damn thing is turning almost dark grey.) Yet, every single Toyota I see with a K&N typically has soot/residue/contaminants on the post filter side of the intake system; where non-oiled filter vehicle tend to be fairly clean.
The same is also noticed on many other brands of vehicles, though this can often be hidden by oil puked into the intake ala BMW, Land Rover, Mercedes, Prius, ect. (but usually this is after the PCV hose going into the intake and you can still see residue prior to this, indicating failure of proper filtration.)
I would give a rough estimate of something like 70~75% of the MAF "Failures," DTCs, and/or MAF performance issues I have dealt with have been a result of contaminated/saturated MAFs with... Oiled Filters equipped. Something to consider, K&N/Oiled Filters are very porous filters that give you "performance" (which I am not even going to go into right now) by reducing airflow restrictions; they make this up by using a "tacking agent" such as the oil to act as a filtration medium and catch particulates. Well, IF the tacking agent is sucked into the intake and adheres to the inside of the intake and MAF Sensor what do you think its going to do? Oh right... adhere particulates to itself like its designed! So the fluid itself may not short out the sensor, but the crap stuck to it, which is choking the MAF sensor wire and heating wires might. Or at the very least cause the MAF to not record accurate gm/s readings to the ECM which in turn will create fuel trim issues.
Which brings me to a somewhat final point (because I am trying not to take up everyone's time with my blathering...) all that is extremely easy for K&N to admit isn't their fault. Most people will not chase the dealership or even K&N for their MAF Sensor failing, they'll throw a fit, pay the bill or sell the car; its too much work to chase a couple hundred bucks like that. Even then, K&N can easily squash the discussion by just saying, "you didn't oil your filter properly, its not our fault."
After all did you perfectly measure out the required amount of oil in a graduated cylinder, then aerosolized it in just the correct way, during the correct ambient temperature and humidity, while correctly ensuring proper adhesion prior to installing and using your filter? No? Well, not our fault!
In conclusion I am not saying that K&N causes MAF sensors to spontaneously commit suicide; but there is a correlation between the number of MAF issues I have seen as a result of K&N/Oiled filters being installed on vehicles using modern MAF sensors.
~Post Note
I would kindly ask persons such as [MENTION=66316]1engineer[/MENTION], [MENTION=78273]Jeremy556[/MENTION], [MENTION=83083]rigtec[/MENTION], [MENTION=87687]LTDSC[/MENTION] ect. to peer-review my rant for any erroneous assumptions, false data, and/or improper logic stated in the above statement. I personally verify that these statements have been internally reviewed, accepted, and made to publish on this forum as a personal opinion based upon fact, logic, and experience in the automotive industry and on understanding of how OBDII vehicles and fuel management systems in modern vehicles function; so help me or [MENTION=55855]zopperman[/MENTION] can ban my @$$ off this forum.
