Exactly. It has been placed there for a reason. The same is true for the thing in the #18 post. It looks like a vacuum regulator to me. These missing/ malfunctioning/ incorrectly connected/ disconnected parts are either the cause of your codes or prevent you to find the true cause of the codes.

I hope grim_reaper is reading this. He can fix things with an average of 7.8 words. They are called AutoZam down under.

 

Hard to believe it's stumping you, Tan. Hopefully, both (and many others too) will learn something very soon.

Mazdamech was a great source for me to when I was removing the manifold. I'm hoping he's reading these too. He's also in the Naval Reserve, so there is a great possibility that he has more urgent items to take care of at the moment.

 

At this point I can only suggest these approaches:
1.Make a complete comparison of your set up to the diagrams I posted.
2. Go to a Mazda Parts department and look it up using your picture as a guide.
3. Search this forum for owners of the same model and see if you can revive an old thread or if you can get a response to a private message.

My image searches came up empty.

 

Good points, Tan.

I'll let you know what I find out.

Thanks for all your help.

 

any progress?

Here is a vacuum diagram that I found in our public library database. This one is for the 1.8L V6: