Toyota Repair: 1999 toyota rav 4wd, vacuum modulator, vacuum hoses

Question
Hello, I own a 99 rav4 4wd, P0401 code problem. I checked egr valve and it is working, all hoses seem ok, was told that vsv is a common problem. i looked it up in alldata and cannot seem to locate it. i followed vacuum hoses from modulator down to underneath intake and can barely feel valve, how the heck do you remove this thing!? also how can I test modulator besides looking at filter, any help appreciated, need to fix to pass emissions.

Answer
The vacuum modulator can be tested by removing it then blowing into the bottom port, no air should pass through, if it does the valve should be replaced. The VSV is difficult to get to, I normally remove the right side front wheel and the tie rod end, this will give enough room to get tools on the mounting bracket to remove the bolt and the hoses.