I've searchd, but couldn't find what I am looking for. Yesterday, I was TRYING to change out my spark plug wires and realized that I had a vacuum line hanging loose that I think goes on one of the opti vacuum ports. The large port right under the cylinder 1 sparkplug wire connection is hooked up. Looking at shoebox's website (your site had been a great help many times, thank you), it looks like that vacuum line goes to the intake manifold after going throught a filter and backflow prevention device. The other one should come from the intake elbow down to the smaller port that is real close to the low voltage side
of the opti. My question is what is this smaller port for? Supply air maybe?
Also, did I kill the life of my opti by letting this port stay open like this? I realize that my motor had been pulling in unfiltered air through this tube hanging loose, but what about my opti? Any info would be greatly appreciated. Thanks.

 

The small port on the housing is for the filtered air supply. Unfiltered air would have been going into the opti. Only an inspection of the inside would tell you if there was any concern.