After going into fail safe mode I took it to a shop. They've had it 3 days and can't figure out what's going on.
Dropped the exhaust from the manifolds back and saw no improvement so they don't think the cats are at fault.
The ecu hasn't thrown any new codes, but it is now missing on cyl 4. checked the coil, plug, injector, fuel pressure, wiring, cyl pressure ... good spark and fuel, cyl pressure within normal tollerances ... moved the coil, plug, injector to a different cyl and #4 is still missing. They don't know what's causing it.
Throttle is not responding, but the IAC seems to be functioning as they can adjust the idle through the ecu.
