Agreed... on my other cars that i've used K&N on, I would find the intake tube to be dirty on the inside.
On my old 00 4runner that had a drop-in K&N, my MAF would get dirty every 10-15k miles and i'd get a check engine light.
the dealer would tell me the sensor needed to be replaced, but all it really needed was a q-tip and alcohol. once the sensor was clean it was A-OK.

Now with the Trueflow, i've used it for quite some time now without any problems, the inside of the intake tube is clean, and no MAF sensor problems. (i have 50k miles, using the Trueflow for about 30K of those miles)
I think it's mainly due to the dual density foam, the foam is coarse on the lower part, and dense on the top.

Dan

 

I have read many article on the net regading foam filters. All but the sponser sites have test less filtration than paper and cotton filters. Below is one of the article about foam filter and sand getting into the engine.

http://www.duramax.bizhosting.com/My_Truck/foam.htm

I use TRD filter and have accepted the fact that it has less filtration than oem filter. No added performance as far as I can tell and maybe a slight MPG gain. The TRD seems to have more surface area than the K&N and the housing seem to be of better construction.

 

[QUOTE=The G Man;2858826]I have read many article on the net regading foam filters. All but the sponser sites have test less filtration than paper and cotton filters. Below is one of the article about foam filter and sand getting into the engine.

http://www.duramax.bizhosting.com/My_Truck/foam.htm

QUOTE]

That's an interesting read, it seems though they are comparing an oiled cotton type filter vs. a non oiled foam filter. I myself choose foam due to bad experiences with K&N, and so far i've been very pleased.

And Yes, OEM paper filters are the best for filtration, but imo, not best for performance.

Dan

 

I've had a the True Flow filter on my 4Runner for over 3+ years now. It works great, and you can feel a differnce in power, and I have a V6. I know the V8 definitely give a nice bump.

 

I just saw a True Flow sponsored video on YouTube. They actually claim that their filter media traps more dirt but do not increase the flow rate.

 

I think the comparison was clean paper vs clean gauze vs a dirty foam, and they all dyno'd the same.

 

The foam had 6K miles on it I believe, thats not much for a 50K mile filter. The paper was the same but the gauze had the highest flow but least filtration. Seems to me that the foam is better for off road applications.

 

I put mine in last week before a 1500Mile road trip and I average 18-19MPG most highway miles and thru the Smokey Mountains, TN/NC US321-441 (what a drive and the GX performed very well) at one point with A/C on most of the time. I did not feel much in power increase... maybe I was not more sensitive on that as I was on mileage. I am happy though with the mileage. I think the truflow filter helped

 

What was the part number for the True Flow air filter you all used?

 

part no. 40201. when i ordered it thru www.trueflow.com lexus GX470 was not listed so i searched for toyota and the closest is the tundra 00-06 4.7L which I figured is same engine as ours. i did call someone from there and they confirmed it.

40201 Premium Air Filter Toyota Tundra 3.4L, 4.7L 00-06

for further info on the engine see wikipedia:
http://en.wikipedia.org/wiki/Toyota_UZ_engine

hope this helps.

 

Well, I needed a new one and ordered it. Installed it no problem but...I am getting lower MPG's than before! I was averaging on the computer readout about 14.7 and now, I am getting 13.3.

Any ideas?

Thanks!

 

Try disconnecting the battery for 5-10min, that should reset the ECU.

 

The lower mileage might be because you are trying to see if the new filter produce any increase in power

 

That's what happened with my exhaust

My wife's ave MPG went up, but with me in the driver's seat it went down...I love the sound it makes when I mash my foot down

 

Thanks for the information everyone, esp. the part about k&n dirtying the maf sensor