I was poking around under the hood of my new 7 and i found that the O2 sensor was not pluged in (the wire was cut at the tip of the sensor) This is strange, because the car is still running fine... the only problem is that the idle lopes from 800-1000 RPM when its cold. What problems can i run into without an o2 sensor.
PS the car has HKS F-CON V and a FMIC on the stock twins...

Thanks,
Chris

 

bad gas mileage well you really cant tell a difference and thats it.