mike_04

for the last month i've been fighting the, po171 fuel trim lean code. i fianally took it to a toyta dealer an hour away from where i live...closes one. it ended up that the MAF sensor needed replaced. I've had the k&n filter for five months and i re-oiled it 2 months ago. It ends up that i'am guessing the oil fried the maf sensor bc buddy at the dealership said he's had two other guys with the same thing. any of you guys have problems with the k&n filter?

I tried fixing this code myself in order by

1) new spark plugs (ngk)
2) o2 sensor (toyota)
3) tps (toyota) this park made a huge difference in throtle response
4) cleaned the MAF
5) fixed the problem by replacing the MAF..


i think the tps and the maf went around the same time because for a while i could not drive it without the new tps. ohh ya i was also wondering if anyone has had to replace this part while running anouther filter.

WolfpackTLC

Only an educated guess, but I doubt that the K&N had anything to do with your problem. Why do I say this?

B/c BOTH speed density and mass air flow systems benefit (as far as performance) from higher rates of air flow. I had a K&N on my 3.4 for over 90k, with no ill effects. " Frying " a MAF w/ more air is unlikely. You'd have to force it through at a ridiculous rate, and even then I don't think it would " fry ". Sounds coincidental. People have been running K&N's for years... if they were frying MAF's we'd know by now.

midiwall

Just to help Mike be clear... He's thinking that the _oil_ in the K&N after a re-oiling cycle may have toasted the MAF. (see below)

Bumpin' Yota

I've also heard that excess oil on the filter will fry MAF's.....fortunately I dont have a MAF, I have a VAFM!

mike_04

right it's not the fact that their is more air it's the oil that posibly did it. i was just wondering if anyone has had this problem because i'am thinking about junking it. plus after finding this.

http://www.gadgetonline.com/airinduction.htm

WolfpackTLC

You have a virtual air flow meter? Are you running a plug in box or a stand alone ECU? Anyways.. I'm off topic...

Ahh... I see... the oil. Well.. K&N says their oil is sensor safe, but I'd guess that oil would only make it hang open or closed, and not actually short it out... after all, moisture gets in there too... Hmm... I used to oil the crap out of my K&N... no problems. You got me. Best of luck though!

mt_goat

I have been running a K&N filter for about 50,000 miles with no problems. I am carefull not to over oil it though.

WATRD

You just repeated an experiment that dozens of us have done before you. The oil from oiled filters coats the MAF and that == all kinds of heartaches. Usually it can be fixed by removing the MAF and cleaning it well with contact cleaner, then mopping some of the oil out of the filter.

The filters commonly come with too much oil from the factory and then people oil them too much again after cleaning them. With the Amsoil, I recommend that people mash it between a coupld of towels before installing it, to remove any extra oil. Because of the pleats on the K&N, you can't really do that, instead, if you must run a K&N, after it's clean and dry, just oil it to the point that the gauze starts to change color. If you can see wet spots or droplets, it's got too much oil

At least you know now

mt_goat

[QUOTE=WATRD]if you must run a K&N, after it's clean and dry, just oil it to the point that the gauze starts to change color.
QUOTE]

Yep, that's exactly what I do. And spray just the outside and let it sit for 20 minutes and soak through to the inside. Then look for any white spots and lightly hit the white spots if you have any.

EDGE

Nissans suffer the same fate the oil is killing the MAF, sounds like an issue I don't want to deal with so I stick with OEM filters that are dry

Bumpin' Yota

Been doing searches and came across this...

Vane Air Flow Meter is what I and every stock 3vze has. The question is when the VAFM frys will it induce knock at crusing speeds with OEM timing?

-ToYoTa-

hmmmmm. i run a GREEN filter. a few guys in K&N wanted to make changes to the filter. K&N said no. so the guys started there own filter called GREEN. they at shows will test there filter against K&N in there machine. when we went to K&N table and asked them to test against GREEN instead of the FRAM they always test against they declined to do it. green is also lifetime. and comes with cleaner. i really only cleaned mine once and didnt use but a tad of oil. cause it stats not to over oil. btw. how much was the maf senser? that toyota repaced. i am scared to ask really. after i installed my green filter i removed my factory air box and all. i didnt get the air tube tied up good and it fell onto my fan. becuase i didnt have teh fan gaurd installed. wasnt on the truck when i bought it. and caused a hole on the bottom side of the air tube behind the MAFS.truck wouldnt idle. and would cut off if u let off the gas. took me 4 days and to find it. and 45 dollars at the garage for them to tell me they had no clue what was causeing it. but it was the hole on the underside of the air tube. i replaced my MAFS for $35 for a used one. i think a new one for mine was about $265..and all i really needed was a $10 tube sucks lol but was 100% my fault for not tieing it up better. i also bought the gaurd and put it back in to stop future problems haha

Mad Chemist

Ditto on what was said above, have heard of numerous occasions of this issue, but never myself. In the end I went back to a paper filter, I'm not sure if the benefit outweighs the disadvantages, what was the stated HP gain for the K&N and Amsoil?

Cebby

Just to reiterate, over-oiling causes issues. I threw a code on my 2000 Maxima from over-oiling a K&N drop in. Use the oil sparingly. Fortunately, a cleaning of the MAF cleared up the problem. I was getting weird performance at WOT, then a code.