would it be harmful to run my maxima ('94 SE DOHC) with the O2 sensor disconnected? How harmful is it to run with a bad one? My car has 106k on it and is very sluggish after the ECU hits closed loop mode, no check engine light but I've been told that a bad sensor won't always trip the CEL.

 

gas mileage will drop alot and it may run rough when cold or when it gets hot