Hoses, sensors and the like (22RE)

[the_dingman]

I like to have an understanding of what things do, and I can't seem to find a good diagram explaining what each vacuum hose on my engine does, and what each one of the few sensors are for. Apart from my work on my two 4Runners, I know nothing about engines, so I'm not good at deducing what things do.

I've seen pictures of fancy 22RE engines with air filters attached to parts of the engine where vacuum hoses are usually attached (like on the valve cover), what are the advantages/reasons behind that?

 

[paragod]

I searched the threads for factory manuals and found a couple of great links to toyota manuals on PDF. They do a good job of laying out the different systems and explaining troubleshooting and the like.