[Porchdog]

O2 bung is just after the collector on the left manifold. There is a significant RPM drop when the oil cap is removed.

I have done a ton of searching for unmetered air - Propane test and smoke test. I found and fixed some fairly minor leaks last year, replaced the warm up regulator with a rebuild one by Tony and replaced the injectors. All pressures are in spec.

No question - it's trying to tell me something. I thought the O2 controller under the seat was bad.

If it happened while I had the car home I think I could find it. by the time I got home last night it was running sweet.

What could allow unmetered air that gets bad, then gets better? And if it's unmetered air, why is it worse at higher RPM's and load?

I'm leaning toward fuel delivery but I can't imagine what would come and go

Thanks