How about using sponge from kitchen, or respirator mask paper or foam from a helmet for examples to cut into shape to fit into the the top of the vacuum controller? I am waiting for anyones answer before I use a sponge, but the issue is If I have to keep pulling the top off: It will break, I know it! Thanks to everyone! Jeff

Some Volvo 700-900 Series FAQ info on the (LOL Cat) EGR

https://www.brickboard.com/FAQ/700-900/Exhaust.htm

https://www.brickboard.com/FAQ/700-900/EngineSensors.htm

There may be more in the FAQ on EGR. I guess you've read through it all.
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THank you again Kitty! No, I have not read everything!
I removed the top of the vacuum Controller on my '91 740 No-Turbo, and yes the sponge had disintegrated: Took a tiny needle in hope of dislodging any dirt in the little hole.
If I take both vacuum hoses off the controller and hold them together, they cause the engine to cough, sputter and reduce rpm significantly: Does this mean the EGR valve is functional?
I am definitely not smart with anything wires but is there other ways to see what I may try to reove or replace if possible?
Thank you so much: Everyone here is so helpful! Jefff

Also is the yellow vacuum hose supposed to be on the upper or the lower part of the controller? Jeff

The EGR vacuum controller solenoid is an open or closed valve based on coolant temperature and maybe some other items like engine load.

The solenoid is open or closed. Maybe connection then does not matter.

Sorry for the very late reply.

Yet follow the hard nylon lines (yellow and white) and see the image Dave Barton hosts at his site:

Please choose model/year in the MODEL/YEAR drop down menus.

Phil Machine Man's post in addressing the EGR controller vacuum valve solenoid doo-hickey with different ways to test and what material to replace the collapsed foam filter at the EGR vacuum controller thingy.

https://www.brickboard.com/RWD/volvo/1650095/220/240/260/280/egr_temperature_sensor.html

Though Phil Machine Man may have additional guidance for you.

Hope that halps.

Please lettuce know how make out.

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Apparently the threaded plug for the EGR pipe port.

Volvo PN 986816

https://www.tascaparts.com/oem-parts/volvo-plug-986816

I'd expect a washer or some manner of sealing mechanism or treatment.

EGR removal may add like 1 MPG to your fuel economy. Yet be certain engine control is delivering a proper exhaust to the catalytic convertor to ensure low NOx. Unless you reside in California, where it is illegal to remove this control. the Volvo VIN includes the factory-installed emission devices.

And verify the air filter box flap valve works for proper preheat mix. Borg Warner Wahler PN 70411. OEM is better quality. The Whaler thermo may need replacement every two years or so?
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