Can someone tell me what is missing here???

[roadmouse]

can someone tell me what part is missing in the picture please?
and what it looks like.
searched my manuals but could not find it.
I think its part of the emission system but thats about all I know

 

[slantsixdan]

An EGR vacuum control switch (3656 660 before March 15 1973, 3780 140 after March 15 1973) or a blockoff plate 3656 649 depending on the vehicle's original emission control configuration. Most of them I've seen, including my '73, have the blockoff plate. The widget next to it is an OSAC valve. Bypass it -- run the distributor vacuum advance hose directly to the correct port on the carburetor -- and you'll have better driveability, performance, and fuel economy with no downsides.

 

[roadmouse]

Thanks Dan!
I know its not a block off plate cause I have a tube coming from the vacuum amplifier nearby tha hole.
and mine is a 73 Duster
by bypass it, you mean remove the whole emission shebang and just get the vacuum advance attached?

 

[slantsixdan]

Right now, the OSAC valve is in the middle of the hose that runs from the carburetor to the distributor. Run a new length of hose between those two end points (carb and dist) without the OSAC valve. The OSAC valve will happily sit there doing nothing, and you'll be considerably happier with how the car runs.

As for the EGR, sounds like your car did have the vacuum control switch. Probably going to be medium-difficult to find a new or working used one. Whether to put the EGR system back together depends on what the engine configuration is and how you plan on driving it (and your local emission laws).

 

[roadmouse]

OK thanks Dan.
as for local emission laws... I'm in Europe, all cars older then 25 are considered oldtimers and as such no emission test is performed at tech inspection.
and this will not be a dailly driver
so I think I will remove it all

 

[slantsixdan]

That's going to be the easiest way. Glad to help.

 

[yellowdartdave]

SlantSixDan is correct.

Only the 340 cars had a blank-off plate as they did not need EGR to pass emissions.

 

[slantsixdan]

Only the 340 cars had a blank-off plate as they did not need EGR to pass emissions.

No, my 40k-mile slant-6 car, with factory-everything under the hood (cap and rotor, vacuum hoses, heater hoses, PCV valve, all EGR components) came with the blockoff plate. So have most of the other '73s I've seen over the years in the yards. The FPC is a little vague on which cars got the control switch and which did not -- California vs. 49-state/Canada, maybe? -- but there were a great many '73s with EGR and without that switch.