This jeep came to me with a destroyed engine, it was half disassembled but only 100K on the clock. NEW engine now and I'm having some issues. After initial startup it was running absolutely pig-rich which was apparently due to to some bad knock-off injectors and a bad map sensor. I managed to do the cam break in, but then got new map and tps sensors, tps has been adjusted correctly and have reinstalled the old, original injectors and seems to have mostly cured the rich condition. I've checked for vacuum leaks at the manifold, seems fine and to make absolutely sure I've got zero vacuum leaks I've got all manifold vac ports capped off with only FPR connected. Also, egr is gone but holes are capped no leaks, have about 18lbs of manifold vacuum. I put a new bosch O2 sensor in it, engine "runs" now but doesn't want to idle well. Idle is low, 500rpm or less, "hunts" and will die, also will die if you let go of the accelerator quickly. The new plugs turned pretty dark from an hour or so from running so rich (yes changed the oil), will the deposits burn off or do I need to replaced the plugs again? The thing I thought was "weird", is when I tried to start it without the O2 sensor disconnected, it ran at 3000 rpm and would not come down at all, but sounded fine otherwise? I plugged the O2 sensor back in and returned to the former described state, low hunting idle. Is that even remotely normal reaction to unplugging the O2 sensor? All I can think of is that my old injectors are in bad shape and need to be replaced and have NO idea about that O2 sensor reaction but have heard jeeps don't like bosch o2 sensors but running at 3k when disconnected is a bit extreme, maybe the ecu needs to be reset? Apologies for the long winded description, any ideas appreciated.