Okay so today I thought I'd install my Xenon Depot HID kit. One look at how tight everything was and how much was going on in the area and decided to hold off until I had more time. While putting all the parts back including the air box assembly I noticed that the lid cover had this 2nd filter attached to it so I was like wtf why do you need that thing for? I guess lexus wanted to have a back up filter for lazy people who don't change their air filters often enough and just wanted a 2nd layer of protection. So being that I wanted to have SOMETHING accomplished today I decided to get rid of the 2nd filter. I never had any other car that had a 2ndary filter like this anyway so what the heck.

Pretty straight forward. Just take a flathead screwdriver and pry off the filter at the mounting points. I broke the mounting points but who cares nobody will ever know the difference and putting back to stock is easy if you ever wanted to. After getting the filter off I knew it was a good idea because the 2nd filter was thicker than I thought it was initially. I thought it was 1 layer of thin mesh but it's actually several layers thick and would one day get all clogged up with dirt anyway so getting rid of it was a good thing. After putting all back together didn't notice much if any power increase but didn't expect any either. Maybe a little bit better throttle response but that could just be my imagination. I'm sure there's a power gain but maybe like 1/4 hp if that much. Anyway here are some pics

stock airbox with secondary filter on



pry these mounting plastic mounting points off, careful not to break the frame of the filter



off it comes and thicker than I thought it was



all gone



more power? maybe... better flow for sure though.

 

I was thinking the same thing last week, that 2nd filter is def. very restrictive, i tryed to
blow through it and didnt feel any air on my hand, lol, (obviously much more pressure when the engine is running).. I dont see dirt getting past the first filter.. I'll probably do mine next week..

 

More Power? Definately not
Better Flow? Yes.... of dust particle that will eventually harm your MAF.

But hey whatever floats your boat its a new car it wont harm you in the
next five years or so but the second owner will.

 

many others cars dont have this secondary filter, its fine

 

Yeah right you gotta be kidding me... there's no way getting rid of the 2nd filter is going to affect your MAF unless your main filter is crappy to begin with. No other cars that I've seen has that 2nd filter on there. I think it's just Lexus being overly cautious. Having said that those with oiled aftermarket filters like K&N's might want to keep the 2nd filter on for back up in case of over oiling. I think everyone should do this minor mod simply because that 2nd filter is pretty thick and serves no real purpose but to choke up your car more than it needs to be.

 

That secodary filter is there for emissions. If I recall from my literature which I do not have next to me at the moment, the filter is there to prevent vapor from being released back into the enviroment.

I do not think there would be a significant impact on performance by leaving this filter in place, however I cannot prove this since only a dyno can really reveal that, but for the sake of the environment I would encourage people to leave it in for the sake of our planet.

 

i agree.. and anyways, if it doesnt benefit performance much, why mess with it?

 

Any change in your MPG? If air is more efficient that would at least improve your mileage. The question is whether or not if it is a significant amount.

 

what vapor, the engine gas recirculation doesnt go anywhere near the filter element

 

I'd just make sure to pay closer attention to the primary filter if you're removing the secondary filter. Otherwise, greater air flow can lead to more HP (as on other vehicles), but there's a pretty easy way to test for sure.

 

Also be more careful when you are changing the primary filter that you don't accidently drop a leaf or some other nasty grit down the intake while pulling the dirty one out.

 

I dont think it is a good ideal to remove it. Just wait around to see brand name manufacturers to release more toys for us.

 

How do you come to the conclusion that this 2nd air filter removal will not yeild more power?
Common sense says it will. How much exactly? Who knows, but I would guess it
should make more power than changing our oem primary filters with aftermarket ones..
You need to look at that 2nd filter for yourself, it's pretty damn restrictive.

 

Reducing restriction on airflow won't make HP unless the engine is starved for air. The only time this might happen on our cars is at WOT and even then I doubt the restriction is very much.

 

So going by that theory, aftermarket intakes and exhaust systems don't make any extra HP...Interesting...