with the map sensor off often it will run, but it will dump tons of gas into the engine. The way it works, the more rpm's, the less vacuum your engine makes, thus with no vacuum, or very little, the MAP thinks you have a wide open throttle condition, and is sending tons of fuel into the motor.
on the other hand, with your o2's, they could either be bad, or your thermactor system may not be operating correctly. When your motor is cold, the smog bypass tubing dumps the air into the cylinder heads, which in turn comes out the headers and into the exhaust. This extra fresh air dilutes the exhaust, and convinces your o2 sensors that the motor is running lean, so it richens up the mixture. When the motor warms up, the air bypasses and goes straight into the cats, and the o2's are happy now and does not richen the mixture at all.
You've got a few places to start. The VERY first thing that I would do is take a vacuum reading. If you don't have a vacuum gauge, go buy one, they're very cheap. A stock cammed motor will make a steady 17-20 pounds of vacuum, 17 being on the low side. Fire the motor up, but leave the map connected, and pull vacuum from an unused port on the intake, or unplug the charcoal canister lead from the front and tap in there.
IF the vacuum is low, you've got a leak, and there is your problem. If it's a steady 17-20 pounds, the problem lies elsewhere.
If the vacuum is good, I'd check the o2's. You could either have o2's that are bad and stuck lean, or bypass tubing that's not switching anymore, and permanently richening it up via the lean signal your getting. That's easy to tell, just pull the rubber lines apart at the Y on the pass side. If the air is coming out the top hose while the motor is warm, then it's not correctly bypassing into the lower hose which goes to the cats.
do report back, let us know what you find. There should be plenty of info here to test the o2 sensors, I believe you can do it with a simple voltmeter, but i'm unsure of the procedure exactly.
