At my wits end Bad Idle M42

[1996 328ti]

Initially I had a high idle. I'd take that high idle back now.

After changing numerous vacuum hoses and ICV the idle was normal but still poor gas mileage. But drivable.

I go away a couple months ago for a weekend and come to a rough idle after warming up. Random CEL.

I initially made my own hoses from the ICV - tree - fuel injectors.
Thinking maybe one hose fell off I replaced the set with a factory set.
Same problem.

Replaced 02 sensor.
Same problem.

Next I'm replacing the fuel filter only because it's probably never been changed.

Car also sounds like a diesel at idle once warm.
It's barely drivable at this point.

I've spent $1000 in parts replacing broken plastic parts.
I still have suspension to go.

If I can't get this working soon it's leaving my driveway.
Either to a buyer or to a junk yard.