2000 Integra LS auto random misfire, con’t

Original post here, but I’ll sum it up again on this thread, with new info.
http://www.ericthecarguy.com/forum/8-Service-and-Repair-Questions-Answered-Here/43446-multiple-random-misfires-on-2000-integra-ls-auto

2000 Acura Integra LS automatic. 190k miles. Runs great, 28 mpg, very hard highway driving. Loses a quart of oil every 5k miles OCI (it’s leaking and maybe burning too)

Check engine light has been on for about 2 years, since 150k miles. When the problem first started, it threw a random misfire code, CEL blinked under load, and backfired. The light mysteriously turns off a few times a year and will come on again a few days later (just enough time to get inspection done). These symptoms are now gone.

Currently, I see a misfire code. P1399, and all 4 associated cylinders misfire codes, and P0420 (cat efficiency code, very recently, guess it finally burned out). No backfires, engine runs very smooth.

Parts changed: cap, rotor, coil, plugs, plug wires, fuel filter, 4 fuel injectors, pcv valve, spark plugs.

Procedures perfromed:
cleaned FITV/IACV
checked for vacuum leaks using ETCG method
Valve lash
Compression test: 4, 3, 2, 1 (200 psi, 195 psi, 190 psi, 195 psi)
Power balance test (engine slowed down on removal of all 4 wires), okay
Fuel pressure (within helms spec)

Bought a scan tool:
Primary 02 reading – back and forth with and average of .41, looks okay.
Secondary 02 – all over (blown cat)
Short-term fuel trim % – min 7% average 8.9% max 10%
Long-term fuel trim % – 4.7%

The only things left I think are: doing a formal vacuum check, MAP sensor, IAC valve, fuel pressure regulator, and 02 sensors. If I can fix the misfire, I’ll buy a cat.

Any help would be appreciated, thanks.