So I'm looking in the airbox to see if there's some sort of quick mod to be had to increase airflow (like the deckplate on the 3.4L V6's), and notice this "secondary" filter more or less permanently attached up under the lid. What is the point of this? Just some sort of "if the owner is a retard and forgets the filter, this will keep the big stuff out" type of catch-all, or does it serve an actual purpose besides impeding airflow? It has a plastic mesh over it and doesn't look very tight in the fabric weave, but I suspect it would at least catch sand and similar nastiness.

I don't know what it is, but I don't like it. Seems like a rather stupid way to decrease airflow to the motor (unless that's how they make it qualify for LEV status?) and I'm really tempted to make it go away "on accident".

Still need to check behind the intake tube that connects to the quarter panel to see if there's an "L" in there which would slow airflow like the 3.4's have. I'm hoping that's just a straight-through to the free world, which would make the stock intake design actually pretty good, except for that stupid second filter.

 

My dad's v6 tundra has that. The l tube is pretty beefy and non restrictive. I believe that prefilter is to comply with today's emmision standards however im not entirely sure.

 

If I can get it out of there without destroying the thing, I might have a go at it (once this snowstorm leaves). Just want to make sure I can get it back in there if I actually do need it. I know the tube from the airbox to the intake manifold is actually pretty good (except for that noise canceller, though that won't account for too much loss) but I'm still curious to see the port on the airbox to the sidewall myself.

May have to leave the edge of that prefilter thing in there as well since I have a hunch it is part of the seal to the real filter. We shall see. There did look to be a small amount of dust on that prefilter as well, though I did knock a ton of ˟˟˟˟ out of the filter (surprising, since I bought the truck used just 1,000 miles ago with a supposedly new one) so who knows. Prolly just going to drop an AMSOIL in there and be done with it. Just knocking the OEM paper one clean made a big difference! I really get the impression this motor responds well to better airflow.

 

The permanent filter in the lid is for the emissions status. Something to do with fuel vapors when you shut off the engine. As far as the fender tube, I pulled mine and cut it flush with the inner fender (still breathing from the fender) and cut out as much tube in the box as possible. Virtually no change in mileage or 0-60 times. IMO not worth the effort.

 

Will the deckplate mod do anything for the Tundra?