petesko

Help! getting multiple misfire codes (0301,0302, etc...). Here's the history-
had a misfiring problem, chased it around until I determined it was a blown head gasket. Since I've replaced the gasket, the motor has run rough, and exhaust pipe is sooty like it's running rich. It sounds great at startup, then starts running rough in a few seconds. The engine is 100% stock, no mods. Here's a list of new parts installed:
reconditioned head (cleaned, shaved, valve job, valve seals, all by professional machine shop)
head gasket
iridium plugs
aftermarket wires
New distributor, cap, and rotor
new timing belt
new water pump
valves adjusted
fuel filter
air filter
fuel pump and tank sock filter
oil and filter changed
transmission fluid changed
Idle Air Control Valve (a few months ago - it was idling up & down)
I thought it might be a sensor issue, so today I checked the following with a volt/ohm meter as shown in the Chilton Manual;
O2 sensor
Engine Coolant Temp sensor
Manifold Air Pressure sensor
Throttle Position sensor
All of the above were within normal range, except for the O2 sensor, which varied from .4 to .9 volts, and the manual calls for a range of .1 to .9 volts when running.
I hate to keep throwing money at this thing without fixing it. I think it's doing worse the longer I drive it, maybe because the rich mixture is fouling the plugs. I put these plugs in after replacing the head gasket and it ran a little better, but is getting worse now. It's running worse now than it did with a leaky head gasket! I'm tired of throwing money at this thing, but I'm in so deep, I just want to fix it. The car has 117,000 miles on it, so I think there's plenty of life left in it. About the only thing I haven't replaced is the electronic control module, but at $300+, I'd like to make that a last resort. Any help would be greatly appreciated!