2003 protege drives rough and giving P0131 code

[Jswillmon]

Hey guys, I have a 2003 Protg ES with a 5 speed. Yesterday while I was driving it I got a CEL but there was no change in performance or hesitation from the car. I took it home and checked it over. It was a little low on oil so I topped it off and unhooked the batter to try and reset the CEL. When I got in it that night It cranked right up with no problem and had no CEL. The problem started when I tried to drive it. In first gear between 2000 and 2500 rpm it would bog down and start to buck, in second gear it would do the same thing only not as bad, in third gear you could barely tell and 4th and 5th felt no bogging or bucking but seemed a little more sluggish.
This morning I drove to work with little problems other than the issue with first gear and right as I got to work the CEL came back on. I just left autozone and found out that it was throwing a P0131 for the 02 sensor. My last protg (automatic) threw the same code and did not bother the performance at all, is the o2 sensor why my car is driving like crap right now or am I overlooking something else. Thanks for your help.
*
Jesse

 

[YenkoZL1]

Its the O2 sensors causing you all the problems. The 02 sensor measures your air to fuel ratio. If one O2 sensor is bad then its not sending the correct info to the computer causing your vehicle to run too fat or too lean. Thus, causing performance issues and it effects milage. O2 sensors are used because there is such a thing as the perfect air to fuel mixture ratio. When your vehicle boggs down like that, it sounds like the computer is leaning out the fuel curve cause it thinks its running too rich. Find out which O2 sensor it is and replace it and be done.