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So, im new here....... hi.
now that that is over with i am having issues with my car, its a 93 civic with a b16 motor/ecu and my check engine light is on. let me review the symptoms

the light doesnt come on right away when i start the car, the car just idles really really shitty, like under 1k rpms.
after about 30-45 seconds the check engine light kicks on, and all is well while i drive.
the exhaust gasses coming out of the tailpipe smell like the fuel is running rich.
i'm really just hoping its the o2 sensor cause that's what the diagnostic said when i took it in to get checked. but other places that i have been online say that other issues can trip the o2 sensor error code.

any advice would be swell

also, i dont really have the cash to replace the o2 sensor till payday, how dangerous is it to drive the car like this? will i be ok for a week or 2 till i can get this taken care of?

thanks for any help you can offer me. and if this is the wrong place for this post, i apologize.