Inside the Air Cleaner Box

[shatto]

This is about my 2006 Toyota Tundra.

It was time, so I removed the air filter that looked like it was made from dirty pajammas and replaced it with a pretty blue Amsoil Ea air filter. I'll blow the dirt off four or five times during its rated lifetime of 100,000 miles.

Covering the entire inside the top part of the air box is a screen that reminds me of the activated charcoal filters in my Army gas mask.
What is the screen and what is it's purpose?

[2000mc]

hydro carbon trap

[shatto]

1. I would think we would want hydro-carbons entering the engine so they could be combusted.
2. There is no float bowl to boil over and cause gas fumes to come out the intake and pollute.

Could you go into a bit more detail? I've never seen such a thing before.

[2000mc]

http://www.visteon.com/company/features/050103.html

thats the first thing a search brought up for me, probly lots more similar info out there




...the air intake system contributes as much as 50% of total evaporative emissions.

http://www.catalysts.basf.com/main/mobile_emissions/mobile_sources/automotive_emissions/air_intake.be