Bought myself a Christmas present. New filter housing to replace the rusty one I currently have. Has an extra port, circled in red, that the original did not. I am just going to cap it, but anyone know what it’s for?

 

Close it off .

 

The new housing really completes your engine bay. I will take a look at a couple of the cars today to find out what it is for. Merry Christmas!

 

smog the car with the rusty one, the smog guy is going to see the open hose and panic.

my guess is that its something for an automatic car?

 

Took a look at a couple of our cars, It looks like it is an 84-85 thing. Both Auto and Manual Have it. No clue what it does as it disappears into the rats nest. I looked at a couple of photos of a 20 thousand mile 83 that I saw earlier in the year and the tube was not there. Like j9 said, use the rusty one for emissions to prevent suspicion, and put the nice one on later. Hope this helps.

 

Looks like the blue line in the middle of the diagram that connects to the vacuum tree. Your rats nest may not include the connection as the configuration did change some year to year.

 

Thank you all. And agree… best to put the old one back on before I go for smog next week. I remember that rats nest / intake diagram from when I rebuilt the engine and carb. I also have a vague memory of being puzzled to exactly what hose goes where as diagram did not match the number of ports on the filter…. Hence the painters tape and numbers still stuck to the underside of the old filter.