O2 Sensor unplugged?

Just wondering if there are any adverse affects to leaving an oxygen sensor unplugged. When my upstream cat is plugged in, the jeep idles like crap, almost stalling, with carbon coming out of the tailpipe. While driving it's fine, just at idle is the problem. I pulled it out today and cleaned it to looking new, but still the same problem.

When I unplug it, the jeep runs fine. No bucking, no carbon, smooth idle. I've been running it unplugged for a little while now, and gas mileage has been the same, so that's not an issue. I'm just wondering if it's fine to just keep running it like that, or if I really should replace it.

spend the $50 and buy a new bosch o2 sensor....why take a chance on your jeep running lean and blowing the motor?

yeah, I prob. will. but since it's just a trail rig, i didn't know if it was a big deal or not.

Probably not the hugest deal. Depending on the year of your jeep, but if I remember right, the upstream adjusts your a/f ratios. If you unplug it, you will get a CEL and your computer will run kind of a "safe mode". You might not notice any difference, but there will be a loss of power, fuel mileage, and bad ratios might lead to taking out your cat faster I would assume. Worth replacing, yes. Park the jeep until you do so? Nah.

Also note they are fairly sensitive, if you cleaned it up until it looked new its definately in need of replacement.

i'll be replacing it soon enough.