Maf sensor

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

IslandCruiser808

IslandCruiser808

Joined
Dec 14, 2022
Threads
7
Messages
24
Location
Hawaii Island
Today I cleaned my maf sensor and when I was finished I reconnected the battery and let it run for about 20 minutes. It has a weird idle and definitely not like it was before I did the cleaning. I also changed out my air filter. I had a check engine light that came on after I had it in the shop for a radiator and alternator replaced. I ran a obd scanner and it came up as PO171/ system too lean bank 1. Most likely fix is to replace mafs. I ordered a new OEM from eBay but won’t be here( Big Island) for ip to a week. So I researched and found that it can be cleaned. I did the cleaning according to the info on this awesome forum. When I turned it over it has an undulating idle. After about 20 minutes of idle it has calmed down slightly but still there. Was thinking of going out and picking up an after market one and using that till the Yota one comes. Any thoughts or recommendations anyone can give me would be greatly appreciated. Aloha
 
IslandCruiser808 said:
Today I cleaned my maf sensor and when I was finished I reconnected the battery and let it run for about 20 minutes. It has a weird idle and definitely not like it was before I did the cleaning. I also changed out my air filter. I had a check engine light that came on after I had it in the shop for a radiator and alternator replaced. I ran a obd scanner and it came up as PO171/ system too lean bank 1. Most likely fix is to replace mafs. I ordered a new OEM from eBay but won’t be here( Big Island) for ip to a week. So I researched and found that it can be cleaned. I did the cleaning according to the info on this awesome forum. When I turned it over it has an undulating idle. After about 20 minutes of idle it has calmed down slightly but still there. Was thinking of going out and picking up an after market one and using that till the Yota one comes. Any thoughts or recommendations anyone can give me would be greatly appreciated. Aloha
Click to expand...
If you have an OEM MAF installed I would leave it in. Please make sure new MAF from EBay is legit. Also is it possible your idle hasn’t changed you just are listening extra close? My 2001 has a slight “cycle” to the idle. Just wondering. Good luck!
 
AARONTLC said:
If you have an OEM MAF installed I would leave it in. Please make sure new MAF from EBay is legit. Also is it possible your idle hasn’t changed you just are listening extra close? My 2001 has a slight “cycle” to the idle. Just wondering. Good luck!
Click to expand...
Yes the account that I purchased from is octoyotaparts. They have a pretty high rating. No the other maf in it now is aftermarket. The cycling idle definitely is new, although I drove the truck for about an hour or so and it has calmed down quite a bit but still there. I am hoping that the new sensor will clear it. Thanks for your reply!🤙.
 
Never install A/M sensors!
 
IslandCruiser808 said:
Yes the account that I purchased from is octoyotaparts. They have a pretty high rating. No the other maf in it now is aftermarket. The cycling idle definitely is new, although I drove the truck for about an hour or so and it has calmed down quite a bit but still there. I am hoping that the new sensor will clear it. Thanks for your reply!🤙.
Click to expand...

If the MAF sensor was really dirty there's a possibility your engine was compensating and now with clear readings it's trying to re-adjust.
 
Aloha.
The P0171 is referring to a specific bank (1) air-to-fuel error outside the threshold Toyota set on the factory ECM.
The MAF sensor could be the culprit but try to dig deeper and check related components like your spark plugs, coil plugs, intake hose line, vacuum lines for leaks/cracks/breaks, and lastly your upstream and downstream O2 sensors.
 
OEMGUY0720 said:
Aloha.
The P0171 is referring to a specific bank (1) air-to-fuel error outside the threshold Toyota set on the factory ECM.
The MAF sensor could be the culprit but try to dig deeper and check related components like your spark plugs, coil plugs, intake hose line, vacuum lines for leaks/cracks/breaks, and lastly your upstream and downstream O2 sensors.
Click to expand...
Thanks for your reply. I’m not mechanically inclined,and I don’t have the funds to send her back to the shop,but I do have some tools and will do some research to learn more and check the stuff you pointed out. Trying to find an affordable mechanic here on the Big Island is pretty difficult. Not to mention the price of parts. Lol
Thanks again.
 
Make sure all vacuum lines on. Ones often miss to reattach or even fall off. Are the two from idle up control. Idle up control, is on vane (power steering) pump. When left off we can get a rough idle and to much air (lean condition) in fuel mix.

A P0171 DTC confirmed. Is BK1 (left as you sit in vehicle). Also check for pending DTC. Which you may have a pending BK2 lean. I Record any DTC, then clear all DTC. See what is any return.

If P0171 returns. Concentrate on that bank, first. If both BK 1 & BK2. MAF is suspect, since you just touched it.

Idle up control.
Engine before washing 11-9-13 (4).webp

009.webp
 
We could go into to list of possibilities for just a P0171. Before going down that rabbit hole. Recheck your work and look for vacuum leak.
 
IslandCruiser808 said:
Today I cleaned my maf sensor and when I was finished I reconnected the battery and let it run for about 20 minutes. It has a weird idle and definitely not like it was before I did the cleaning. I also changed out my air filter. I had a check engine light that came on after I had it in the shop for a radiator and alternator replaced. I ran a obd scanner and it came up as PO171/ system too lean bank 1. Most likely fix is to replace mafs. I ordered a new OEM from eBay but won’t be here( Big Island) for ip to a week. So I researched and found that it can be cleaned. I did the cleaning according to the info on this awesome forum. When I turned it over it has an undulating idle. After about 20 minutes of idle it has calmed down slightly but still there. Was thinking of going out and picking up an after market one and using that till the Yota one comes. Any thoughts or recommendations anyone can give me would be appreciated
Click to expand...
 
Aloha guys. Just a follow up on my Maf/ Idle issue. I went back to check on my work and as 2001LC stated, go back and check for vacuum leaks, I did find one of the hoses coming from the vane was not attached. I put it back on and the idle has gone back to normal. I’ve put around 50 miles on it and the check engine light has not come back on. So now I’m just waiting for the new OEM maf sensor to arrive. A big thank you to everyone that replied and steered me in the right direction. Now I’m on to finding the PS leak after I give it a good cleaning.
 
IslandCruiser808 said:
Aloha guys. Just a follow up on my Maf/ Idle issue. I went back to check on my work and as 2001LC stated, go back and check for vacuum leaks, I did find one of the hoses coming from the vane was not attached. I put it back on and the idle has gone back to normal. I’ve put around 50 miles on it and the check engine light has not come back on. So now I’m just waiting for the new OEM maf sensor to arrive. A big thank you to everyone that replied and steered me in the right direction. Now I’m on to finding the PS leak after I give it a good cleaning.
Click to expand...
Perhaps try some at-205 for the leak…
 
MAF sensor is a very sensitive instrument. Even cleaning cam result of derogation of signal.

Personally, I use only ones I've purchase from Toyota. To much junk on ebay, amazon, INDY parts stores.
 
PS system capacity .9 qt. ATF (see res cap). So use only 1.33 (1.5oz max)

AT-205 will help with:
  1. AT-205, will slow or even stop input shaft of pinion leak. But it will not last, more than 1 to 3 years. We're just buying time. Until we replace the R&P.

AT-205 will do little to even slow:
  • AT-205 will do little to even slow, a Vane (PS pump) leak. If a vane leaking at shaft seal (in front). it needs to removed and replaced (R&R). As this is sign bearing shot. These leaks can get very bad. They require adding ATF constantly. If allowed to go for to long, other parts will be damaged. i.e. Alternator, Rack mount bushing, LCW bushing, frt diff bushing.
  • AT-205 will do little to even slow, output shaft of rack seal leak. The bottom of boot(s), over inner TRE. Fill with fluid then, then leak from bottom side of bottom. You can slow this/these rack seal leak. But I've yet to see it stop the leak. R&P must be R&R
  • AT-205, will do nothing to stop hose leaks. Hoses. must be R&R.

AT--205 will help with:
AT-205, will slow or even stop input shaft of pinion leak. But it will not last, more than 1 to 3 years. We're just buying time. Until we replace the R&P.

2001LC

Thread 'Steering Flush & Cleaning'

Cleaning power steering reservoir and flushing it's fluid. Keeps Vane pump and rack & pinion in top condition.

These step will help you get, a better idea on how to.
  1. Power wash reservoir & hoses using a degreaser, before starting service. Makes for cleaner job. Repeat, once all done with servicing/flushing.
  2. Release hose clamps from hoses of reservoir, sliding them down the hoses a few inches. Do not remove hose yet, just insure they turn freely on reservoir nipples.
  3. Pull reservoir out of holder. You'll need to release/bend clip outward, on outside of holding bracket...
  • Like
 
Last edited:
You must log in or register to reply here.

Share this page

Back
Top Bottom