Code 94, help!

AIR system inoperative - Air Injection... I can't seem to get rid of this code! Codes 44 and 94 usually appear together, but what I've read on this forum indicates a lone code 94 has something to do with the air diverter valve. I've checked the vacuum lines and they are good. The solenoid seems to be working normally as the vacuum line attached to the diverter valve has vacuum when the engine is cold, and no vacuum when the engine is warm. I disconnected the two hoses after the diverter and tested the valve by applying vacuum and felt air from the smog pump divert from one hose to another. Some people have said that a code 94 could be because of a clogged air tube that runs from the diverter to the heads. Others think that an O2 could be bad, although my O2's only have about 30k miles on them so I doubt that they went bad already, but who knows.

Both my KOEO test along with my cylinder balance test passed. I don't have any other KOEO codes. If anyone has any other ideas or clarification on code 94 please post!

Today I hooked a length of hose up to the check valve and blew into it, air was flowing with relative ease. When I tried sucking the valve would close and I would get no air flow. I tried taking the air tube off, but it seems stuck on with the might of god. I sprayed some PB blaster on the bolts in an attempt to free them, but if I was able to blow air, is removing this tube a waste of time?

How does the computer know what side is getting air? I didn't see any sensors on the pipe, do the O2s detect this airflow?

Just an update:

The tube and passenger side's head passageway were both blocked up pretty badly. I sprayed the tube out with carb cleaner for a while and got it flowing much better. The passage in the head was kinda a pain. I stuck a vacuum line in the passage and sprayed carb cleaner into it. After the gunk was softened I was able to push the vacuum line in further and the crap was pushed into the hose. I pulled out the vacuum line and blew all the goo out of it then repeated this procedure until I was able to freely blow into the passageway through the hose.