Cleaning the MAF

is your K&N in the stock airbox or a CAI??

and who cares about fine dust... I didnt tighten my K&N down enough and forgot to do it before I went 4wheeling, I sucked up hours of dirt and dust and my 4runner still ran fine, I do have an intermittent low idle, but hours of dirt sucked into the engine and the worst problem I have is to clean my MAF and my IAC valve? I love toyotas!

I had never cleaned the MAF before, and Im at 195k so I figured I might as well do that,

with a K&N CAI all you have to do is take off this and spray in the hole and around the assembly... super easy

I was shocked at how smooth and how much more power I had after doing this...

I used both the drop in and CAI. I used to run them in all my vehicles. Not no more. What part is that? I don't recall seeing that on mine...
 
I used both the drop in and CAI. I used to run them in all my vehicles. Not no more. What part is that? I don't recall seeing that on mine...

thats a shame, I get so much more hp and torque from the K&N,

the part you are asking about is labeled "M" in this pic, its all thats left of the mass air flow stuff when you remove the stock airbox.

pretty much that whole piece between the tube and the box.
 

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code P0420

After driving 40 miles the light came back again,:cry2: this time only with P0420.
The Ox sensors back and front has been replaced (around 2 years ago for the front and 8 mos. the rear). I can not understand the fuel trim #3 to be -100.6% for long and short trim. I will have to check some more here.
Thank you for the replies.
 
After reading this last night, i made it a point to do it this weekend on many cars we have. Here are the results.

1. Toyota 4Runner 2007 55k miles - Sensor was clean. Cleaned it anyway.
2. Honda Accord 2007 95k miles. Sensor super clean. Cleaned it anyway.
3. Lexus IS 300 2004 48k Miles. Sensor clean. Cleaned it anyway.
4. Infinit QX56 2006 50k miles. Sensor clean. Cleaned it anyway.
5. Honda Civic Hybrid 2008 48k Miles. Sensor clean. Cleaned it anyway.

Also measured Air Flow/Min using the ELM scanner before and after. It said the same thing after the cleaning. I guess they were all good.

I was hoping that the accord would have some dirt, but it didnt have any. I could see the shiny resistor like thing. What i saw so far

Honda and Infiniti use the same sensor, made by Hitachi.

Toyota 4runner and the Lexus is300 use the same sensor made by denso.

Coming back to this topic of cleaning i have seen many pics here with dirty sensors. I am wondering why mine is clean even after 93k miles(honda).

Two factors,

a) Always use OEM filters. No After market filters period.
b) Dont live in a smog filled city where dust and soot are a problem

This actually prompted me to think that the MAF sensor cleanliness could be a good measure of how other after market filters are working like K&N. If you have K&N and have been replacing/cleaning it regularly and the MAF sensor is dirty, then there is proof right there that the K&N is not filtering everything. Air flow has taken priority over filteration.

If you have been using OEM filters and your sensor are still dirty, then you must live in a smog/soot filled city or drive in very dusty conditions.

As for me, this has reinforced my belief that the manufacturers have found the right balance between air flow and filteration so its OEM filters for me all the way. And also feel better than they got cleaned anyway.
 
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Funny this is my thread... I started using a K&N a couple months ago and got P0170, a dirty MAF. Cleared it and cleaned the MAF and went back to normal. Washing the K&N cleaned a lot of crap out of the filter, I was surprised. The recharge kit comes with plenty of oil for numerous cleanings. If you keep up with how the filter is designed to be used, then you really shouldn't have any problems. Just wash and re-oil no less than once every 2 months, and you should be fine.
 
Funny this is my thread... I started using a K&N a couple months ago and got P0170, a dirty MAF. Cleared it and cleaned the MAF and went back to normal. Washing the K&N cleaned a lot of crap out of the filter, I was surprised. The recharge kit comes with plenty of oil for numerous cleanings. If you keep up with how the filter is designed to be used, then you really shouldn't have any problems. Just wash and re-oil no less than once every 2 months, and you should be fine.

Thats my whole point. Inspite of the dirty OEM filter the MAF Sensor was clean.

If the MAF was dirty, i can only imagine the grime and dust thats eating up the pistons and rings.
 
My engine light just came on this week after 11.5 years and 105k. I took it over to autozone and got the code that says I'm running too lean...at which point I found this thread. It's been very helpful, along with this instruction set (4Runners.org - Cleaning Your Throttle Body and MAF).

I was able to pull my MAF sensor out (after stripping and then dremeling the screws)...after spraying it with contact cleaner, it looks like one side still has some sort of deposit on it. The wires are clean, but the top part has a gray material on one side, the other side is clean looking amber.

Any further steps I should take?


Thanks.
 
Use MAF cleaner. It's made specifically for that. Also you don't have to remove it to clean it I find it much easier to remove the air filter and hose from the top end and just spray the hell out of it. Then just leave your hood up for an hour to let it dry out and reconnect.
I'm not sure exactly what contact cleaner is but use the right stuff and you shouldn't have a problem.
 
After reading this last night, i made it a point to do it this weekend on many cars we have. Here are the results.

1. Toyota 4Runner 2007 55k miles - Sensor was clean. Cleaned it anyway.
2. Honda Accord 2007 95k miles. Sensor super clean. Cleaned it anyway.
3. Lexus IS 300 2004 48k Miles. Sensor clean. Cleaned it anyway.
4. Infinit QX56 2006 50k miles. Sensor clean. Cleaned it anyway.
5. Honda Civic Hybrid 2008 48k Miles. Sensor clean. Cleaned it anyway.

Also measured Air Flow/Min using the ELM scanner before and after. It said the same thing after the cleaning. I guess they were all good.

I was hoping that the accord would have some dirt, but it didnt have any. I could see the shiny resistor like thing. What i saw so far

Honda and Infiniti use the same sensor, made by Hitachi.

Toyota 4runner and the Lexus is300 use the same sensor made by denso.

Coming back to this topic of cleaning i have seen many pics here with dirty sensors. I am wondering why mine is clean even after 93k miles(honda).

Two factors,

a) Always use OEM filters. No After market filters period.
b) Dont live in a smog filled city where dust and soot are a problem

This actually prompted me to think that the MAF sensor cleanliness could be a good measure of how other after market filters are working like K&N. If you have K&N and have been replacing/cleaning it regularly and the MAF sensor is dirty, then there is proof right there that the K&N is not filtering everything. Air flow has taken priority over filteration.

If you have been using OEM filters and your sensor are still dirty, then you must live in a smog/soot filled city or drive in very dusty conditions.

As for me, this has reinforced my belief that the manufacturers have found the right balance between air flow and filteration so its OEM filters for me all the way. And also feel better than they

got cleaned anyway.

OEM v Aftermarket does not matter like you say, it's personal preference I most likely have the dirtiest/most mud filled K&N drop in anyway has ever seen as is been soaked in mud and dirt and have yet to clean my MAF, not to mention I live in a pretty large city. Anyway my point is I have got no codes (knock on wood) at 105k miles you're little theory/belief doesn't hold up. As for your Honda at 95k miles and clean MAF how many times has that thing been offroaded? I didn't think so, I'm not bashing you just seemed like you were coming off at aftermarket filters like they're useless
 
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Just cleaned my maf today. I too stripped the screws out, I would suggest getting 2 little 4mm screws at the same time. They were 20 cents each at DeNaults. Beats running back and forth getting them.
 
I finally got around to cleaning my MAF and Throttle Body today. I took the Air Filter Box out so I had clear access to the MAF housing screws and managed not to strip them this way. The side of the wires facing the air flow were dirty and cleaned right up after spraying the crap out of them with the MAF Cleaner.

To clean the Throttle Body I ended up removing it to get the inside portion as well. The outer intake side wasn't too dirty but the back side was really bad. There was a thick layer of black oily crap which took some work to clean out. While I had it apart I also took my Dremel to the gasket and removed the flat portion so it's round now. May not see any gains out of it without a SC but what the heck.

I took out the 20 AMP EFI fuse before I started and put it back in when finished. The fuel pump ran for a bit when I turned the ignition to "on" but the Runner started right up with no codes.... I drove it for a bit and didn't notice any any real HP (seat of the pants) gains but it sure runs a lot smoother and idles smoother. Seems to accelerate a bit faster.
 
Of those of you that clean MAF and TB on a routine basis, what are your intervals? I don't recall Toyota specifying. I've been doing MAF every 15K and TB every 30K when I do the plugs since I took over maintenance at 30K. I have had no problems with this approach. Both seem to need it when I do it but not overly so. I have a stock air filter (and 4mmx12mm Allen screws in my MAF.)
 
My engine light just came on this week after 11.5 years and 105k. I took it over to autozone and got the code that says I'm running too lean...at which point I found this thread. It's been very helpful, along with this instruction set (4Runners.org - Cleaning Your Throttle Body and MAF).

I was able to pull my MAF sensor out (after stripping and then dremeling the screws)...after spraying it with contact cleaner, it looks like one side still has some sort of deposit on it. The wires are clean, but the top part has a gray material on one side, the other side is clean looking amber.

Any further steps I should take?


Thanks.

I went and grabbed some Mass airflow cleaner and sprayed down the sensor about 3 weeks ago - while I was in there I also sprayed some carb cleaner into the throttle body and cleaned it out. After all that I pulled the battery cables for a while to reset the check engine light and it stayed off for 3 weeks and 600+ miles, until this afternoon when it lit back up again. Any ideas on other things I should check/try?
 
I was able to clean mine 2 times and bought myself an extra 8-12 months, then after several good cleans I bit the bullet and bought a new MAF sensor.

Give it a dew good cleans. If the light is still on you may have to buy a new one.
 
I was able to clean mine 2 times and bought myself an extra 8-12 months, then after several good cleans I bit the bullet and bought a new MAF sensor.

Give it a dew good cleans. If the light is still on you may have to buy a new one.

Thanks - my light actually went off after about 2 days...I'll probably try to take it apart again in the next weekend or two and clean it again anyway.
 
I cleaned my MAF today with air intake cleaner, not realizing that there is a MAF-specific cleaner. Is there any chance I could have wrecked the delicate sensor by spraying it down with intake cleaner? Or should I be ok as long as I clean it with the MAF cleaner tomorrow?
 
I cleaned my MAF today with air intake cleaner, not realizing that there is a MAF-specific cleaner. Is there any chance I could have wrecked the delicate sensor by spraying it down with intake cleaner? Or should I be ok as long as I clean it with the MAF cleaner tomorrow?

oh wow... intake cleaner I think is pretty corrosive isnt it?. The thing about MAF cleaner is that its safe for electric parts, and it evaporates quickly.

I would cross my fingers on that one. Maybe if you didnt let it collect in there. Even with the MAF I make sure that I dont let the fluid sit inside the cavity.

I actually turn the sensor toward the ground and spray up at the sensor so no fluid sits in there.

You should know pretty quick if you did mess it up.
 
I cleaned my MAF today with air intake cleaner, not realizing that there is a MAF-specific cleaner. Is there any chance I could have wrecked the delicate sensor by spraying it down with intake cleaner? Or should I be ok as long as I clean it with the MAF cleaner tomorrow?

Way back when , dedicated MAF cleaners were not well known. Lots of folks would use intake cleaner. Mostly they were fine, but people switched to MAF cleaner for good reason once it became widely available. I used intake cleaner on mine the first time and it is still in the truck at 143k. I'd give it a shot with MAF cleaner to remove any residue and hope for the best.

Now BRAKE cleaner would be a very bad idea.
 
OEM v Aftermarket does not matter like you say, it's personal preference I most likely have the dirtiest/most mud filled K&N drop in anyway has ever seen as is been soaked in mud and dirt and have yet to clean my MAF, not to mention I live in a pretty large city. Anyway my point is I have got no codes (knock on wood) at 105k miles you're little theory/belief doesn't hold up. As for your Honda at 95k miles and clean MAF how many times has that thing been offroaded? I didn't think so, I'm not bashing you just seemed like you were coming off at aftermarket filters like they're useless

100k miles is a lot of distance for anything to get dirty. I stand by what I said. If your MAF sensor is dirty your air filter is the culprit, period. Dont need more proof. Whatever brand filter you use does't matter. My experience with OEM filters has been excellent. I can't vouch for after market filters as I have never used them and will never use them.

I mentioned it only after I saw some pictures posted by others of their MAF sensor that looked like crap and they said they used after market filters.
 
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