icerunner

I used a pre-oiled filter and soon after I drew a code PO171 bank 1 lean. I think the pre-oiled air filter had too much oil on it right from the box..Switched out the filter w/ OEM yet code remains... so it could be something else..? Maybe a vacuum leak..?

PO171 bank 1 lean...Tried spray cleaning with MAF cleaner and I still draw the code. Is there a way to LIGHTLY clean the MAF with a Q-tip without damaging the MAF Wires?

Other things I did:
1) changed spark plugs
2)changed Fuel Filter (Wix).
3) cleaned throttle body
4) changed PCV
5) used Techron FI cleaner on one full tank and Shell V-power on another

Note: at high RPM's on the HWY acceleration I sometimes get a very brief pinging/clicking noise on the driver's side..

Had the hood up while the engine was running and there was an intermintent clicking noise (every 5 seconds or so).. kind of sounded like a sticky fuel injector?
After running shell V Power for a few tank fulls it seems to have went away.. Bad fuel injector?

Elton

you reset the computer ?

Kiroshu

Well your not ever ever supose to touch or clean the air flow meter because if you do it may never read the same again and ruin it.... but sometimes not.... check for vac leaks in your intake tube....reset comp...

22RUCRAZY

denatured alcohol

Teuf

For general info, explane Comp reset.

brian2sun

Unhook a battery teminal for 30-45 minutes and the computer will reset itself. Once you hook the battery back up, the computer will re-learn how to do things now that the problem is fixed - as opposed to the computer just continuing to compensate for a problem that no longer exists.

If you don't do this the computer will still eventually learn and adapt, but this is faster.

DailyDrive

If you clean the MAF without breaking it, then no, it will not ruin it, and will still read the same. That probably holds true for anything, not just MAFs. Clean it without breaking it, then it won't be broken after the cleaning

Brake cleaner/carb cleaner works best to dissolve serious gunk, and the pressure of the liquid and air in a typical can is just about perfect for doing it. "MAF cleaners" might be too gentle. The sensor wires inside the tip of the MAF should be silver.

BigBallsMcFalls

yeah but...
if you -bend- the sensor wires even slightly it could go out of calibration a wee bit. so it is easy to render these junk if you mess up. better to use MAF cleaner or denatured alcohol (which strips almost everything) and to touching

Motorking

Hello,
I am the technical manager for FRAM. It sounds like you used a Tough Guard air filter. I can assure you that there is no way the "pre-oiled" media caused your lean code. You most likely have some kind of intake leak with unmetered air getting past the MAF. Recheck the installation and look for loose clamps, hoses and possibly the element not properly seated. Be very carefull cleaning the MAF, use only MAF cleaner and do not touch the element. I can email you complete troubleshooting instructions for the P0171 code if you give me the year, and model with engine size.

bgmac

Ya, its not the filter. I used a Fram Air hog for like 9 months with no problems! Whever I clean my MAF/TB I pull the fuse for the ECU before hand and then plug it back in afterwards. Never had a problem. I highly doubt your MAF is the problem. Check your plug wires.

CYi5

CRC electronics cleaner.

icerunner

I'm not 100% sure it was the oil from the air filter so I removed the brand name to be fair..however I will tell you that the oil actually soaked into the box (and discolored it slightly) while it was still on the shelf at the store..

99' v6 3.4L 4x4 SR5: po171 lean code system 1, bank 1.. could be CYL 1 running lean? I did clean the throttle body a while back. Possible vacuum leakage as the rubber and air hoses and duct assembly hoses are 10 years old now..? I wonder if a smoke stick would help?

icerunner

FYI before you buy..

oil from an oiled air filter was caked on to the MAF wires had to lightly clean large wires with a q-tip dampned w/ MAF cleaner worked like a charm. one NASTY oily q-tip after i hand cleaned I think just spraying MAF cleaner had no effect on the large plate wires (99')
NOTE: There ARE TWO small DELICATE ("hair like" small) wires were consealed in the black tube I MEAN SMALL... and they look like they can be easily damaged ...i didn't dare use a q-tip on these... I JUST SPRAYED w MAF CLEANER...A TON of grime came back out of the tube..reset code and perfect...no code no missing, got my runner back.. nice

DailyDrive

Wait, what did you clean exactly? Those hair like wires is what does the measuring of air flow. Nothing else.

icerunner

On my 99' SR5 3.4 L there are 2 sets of wires.
I pulled off the sensor from the housing by unscrewing the 2 screws.
After the sensor is out, I noted 1 wire (Under tube) is exposed in plain view when looked at outside the tube. The other 2 hairlike wires are deep in the tube. Note: If one were to put a Q-tip IN the tube I can see how these wires would break as they are THAT thin.
On my rig the MAF sensor has wires in two locations...1 large wire is out and 2 smaller wires are in NOTE: unless you pull out the sensor from the air box, there is no way to to see or even clean the smaller wires with the spray cleaner.

AustinTaco

For a quick clean of the MAF, and if you have the deck plate mod:

Pull out your air filter and using an angled mirror, look into your intake and see where the MAF is located. Take your plastic safe MAF cleaner and attach one of those tiny red straws that allow you to aim the spray. I turn the can upside down with the nozzle outside of the air box in front of the DP hole. Insert the red straw into the nozzle, and now you can spray the front of the MAF without removing it.
Just wait the recommended amount of time to let the vapors evaporate, and clean up any immediate overspray.

icerunner

Great advice guys..I didn't have to spend a whole lot..Spark plugs were over 30K so those needed to be changed anyway...
Here is what I think happened..the 2 small hairlike wires located IN the black small tube
were allready dirty and the over oiled filter made it worse I.e a sticky dirty mess on the wire surface. As soon as I pulled the sensor from the housing and sprayed MAF cleaner inside the small black tube (1/2 inch tube) significant dirt/grime came out, what can I expect after 10 years and 170K miles... Right?
Someone said 85% of the time lean code are infact a MAF issue..we'll that person was right! Ha-ha issue solved..

delio

well. I had a cel for a few days and took it to a mechanic just to determine the code it's throwing and it is bank #1 burning lean... it is also lagging quite a bit, was told to replace the TPS and O2 sensors and replace the injector, but I just cleaned the throttle body, IAC and MAF... the code went away and my runner is running well again..... I just used a good ol' brake cleaner

hnugen

BRAKE CLEANER or CARB CLEANER! I've used MAFS cleaner and rubbing alcohol and they do not work for caked up oil and dirt, neither does a qtip unless you are really picking at it. Used brake cleaner 20K ago and have restored good gas mileage since.

brian2sun

CRC electrical cleaner or MAF cleaner is best - maybe not for cutting grease and dirt, but better because they don't leave harmful residues like other types of spray cleaners can. Definitely not a Q-tip because the wires are very delicate and can easily be damaged.