Jack
not if it is your pre cat 02 sensor. MCS has one before the cat and one after. The post cat sensor brings the EML light on. Plug a diagnostic in see if there are any codes. Normaly when the pre cat 02 sensors go you have rough running and poor fuel consumption
It could be a number of things MAF sensor can cause this as well. Same a dirty throttle body
It could even be the car having a bad day see what it's like tomorrow.
Hope this help you