MAF Sensor Maintenance

[uphill]

JASON DeMELLO SAVED MY A$$ (again)

On the eve of my North Rim - Grand Canyon/Aztec Caves run with VOLHOO, I started the engine of the FJ.

<CHECK ENGINE> light on

When the check engine light goes on, all of the traction control lights come on and it's quite spectacular.

No problem. I have a ScanGauge2. Yes there are error codes, but none correspond to Toyota error codes.

The rig is driving fine. I run down to Auto Zone and plug in their scanner and it shows the following error codes: P043E, P2401, P2402, P2419. They looked them up for me. They only correspond to Mazda and Volkswagens.

The clerk at Auto Zone picked his nose, rubbed his hand through his hair (I'm not kidding - literally) and told me he had "no idea".

So I drove to ToyotaMasters and spoke with my friend, Eric, who broke out his scanner. All it showed was "error".

W-T-F over?

I hate to bother Jason DeMello, but he's THE genius so I drove to his shop. The diagnosis took all of about three seconds.

MAF Sensor



For those of you who are knowingly saying "of course that's what it is", keep in mind that I am a functional idiot - relying on gauges and diagnostics to cover my ignorance.

The MAF Sensor plugs in behind the OEM Secondary air filter. Oil from the K & N air filter I was running slowly accreted on the sensor over time. Dust attached itself to the sensor (with a minute quantity of oil on it).

So I dumped the K & N filter in the trash (if anyone wants it, it's in Jason's trash - they have a lifetime guarantee - rush over before they empty the trash tonight) and bought an OEM filter - and will be going with paper filters now. Jason took his air hose and blew out the secondary air filter and was COMPLETELY helpful.

Apparently this has been a problem with Tacomas that ran K & N Filters. Jason said that if the MAP Sensor gets too clogged with dirt, it will shut down the engine and the engine won't restart.

Electronic parts cleaner sprayed liberally on the sensor cleaned it up.

For those of you who run in dust a lot as I do and particularly those who are running a K & N Filter - this is a learning point: Clean your MAF Sensor. Because if it shuts down and you're in the back of beyond you may not know why the engine died and won't restart - and the error codes on your ScanGauge will not reflect the nature of the problem.

[layonnn]

Good to know Larry. They always say not to over oil your reusable air filter, but if you have never done it before, how much is too much?!?
Can you go into a little more detail about how it was cleaned? What is "electronic parts cleaner"?

[kokopelli]

It's catch-22 really.. Too little and it doesn't filter properly and too much and you got problems. Electronics (or contact) cleaner is a degreaser with other properties helpful to electronics.. The same concept as carb, TB or brake cleaner. Just spray to wash the crap off. Ron

CC-44 Electronic Contact Cleaner and Degreaser

layonnn previously said:

Good to know Larry. They always say not to over oil your reusable air filter, but if you have never done it before, how much is too much?!?
Can you go into a little more detail about how it was cleaned? What is "electronic parts cleaner"?

[Dragon]

I've been instructed by many that it is better to not oil an aftermarket filter than it is to over oil it for this same reason.

[kokopelli]

I believe the newer dry filter (spun/blown/non-woven) technology will eventually displace the wet/oiled all together. JMHO Ron

Dragon previously said:

I've been instructed by many that it is better to not oil an aftermarket filter than it is to over oil it for this same reason.

[Canito is1]

I had this exact problem with my Disco and the K & N. I re-oiled by WAY too much, destroyed the MAF sensor, and luckily was able to find a used one on ebay for around $100. I'm not saying that I dont have a K&N in my FJ now, but I am sure of how much oil I use on the filter these days... can be an expensive problem

[uphill]

For the time being, I'm back to OEM filters until I decide whether or not to go with a different non-oiled filter.

AND I don't oil my K & N much at all. Obviously too much, but it's not worth the hassle. I'd rather pay more for the OEM replacements.

[sandabbe]

I thought this was going to show us how/where/ to clean that sensor, you know with pics and everything!!! (oops i see a pic has been added!, my bad!)
Although Scott probably knows where the thing is! LOL!!! He checked the K&N after the run this weekend and said it was looking good(meaning its dirty and working fine)! Hope its ok??? I'll be sure to direct him to these threads!!!

[Dragon]

uphill previously said:

For the time being, I'm back to OEM filters until I decide whether or not to go with a different non-oiled filter.

AND I don't oil my K & N much at all. Obviously too much, but it's not worth the hassle. I'd rather pay more for the OEM replacements.

The TRD comes pre-oiled correctly. After market filters allow more air in, and the oil keeps dust out to some degree. If you want after market filters for the increased airflow, you could always just replace each drop in with a NEW TRD every time. I realize that it's approx $75 each time? but they should be good for 30-50k miles. Of course, I'm not running in the dust that you are.

[kokopelli]

If you use a cone type oiled/hi-flow filter, one of the outerskin pre-filters is the way to go. You just wash it out and stick it back on.. Ron

Dragon previously said:

The TRD comes pre-oiled correctly. After market filters allow more air in, and the oil keeps dust out to some degree. If you want after market filters for the increased airflow, you could always just replace each drop in with a NEW TRD every time. I realize that it's approx $75 each time? but they should be good for 30-50k miles. Of course, I'm not running in the dust that you are.