Hi. Thanks for using JA! I will try and help you out.
could you get me your engine serial number please?
Thats OK. I just like to get the serial number to be as accurate as possible.
Here are some images of the air fuel ratio valve. Some of the pics are old and a little grainy.
http://dl.dropbox.com/u/11922365/Fuel%20Ratio%20Control.doc <<<<<click here
Please let me know if you need anything else.