'99 E320 V6 power loss

[rjk]

Car has 180k+ mi.

Can anyone point me in the right direction?
Car suddenly lost power (lots of power) earlier this week but after it sat for an hour it started right up and drove home fine.
Codes were thrown & I had Autozone read them.
Cylinder misfires and PO400 (EGR Flow).
I figured I would look into it this weekend but the car suddenly died again and would not move over 10MPH.
Check Engine light was flashing.
I got it towed home.
No code reader here so I don't have latest codes if any.

I inspected it this AM and there was a buildup of oily crud around the coils.
Thought this might be the cause of the misfires.
I cleaned them & the HT leads (removed & doused with WD-40), changed the plugs (they were due, nothing tell-tale there though), and cleaned out the EGR tube (It was about 95% plugged, EGR valve is new Pierburg this past winter).

I restarted it and it is still exhibiting poor idle/loss of power on acceleration.

Just for giggles, I cracked the air filter box and the engine started idling better but then went back to where it was earlier, a loping miss/catch.
If the throttle is pressed hard, it will stall, pressed slowly it will accelerate fitfully to a point beyond which it craps out.

I checked fuel pressure and it fluctuates rapidly between 52 & 64 PSI at idle, stays at 50 PSI with engine off. Flow seems OK at idle.

Any thoughts? Yeah, I know, a code reader is in my immediate future.

Is it possible there is a memory that I need to erase? Disconnect the battery to purge it like I can do to my old Volvo, will that work?