Finally figured out the vaccum leak ...... well, didn't solve it yet but getting closer
Its coming from the exhaust. The air pump ( which is disconnected) has fittings to exhaust. It sounds like it's coming from there very strong.
Like right behind the the point where the cab meets the bed. I got under it with it running and a helper pressing on the gas and I could hear it very strong from the exhaust
As I recall those fittings are check valves. I’ve replace a few in my days. I’ve seen those valves go bad and take an air pump out. Also seen catalytic converters be the cause of it all. Just my 2 cents.