I own a 98 cobra just had a engine light come on when to AutoZone they said oxygen sensor driver side front before cat so I did that ... Did not fix problem anyway car is bucking at 2000 to 2500 AND rough idle at start sometimes stalls to .... Wanna fix and all help much appreciated thanks

 

after replacing the sensor did you have the light/ecu reset to clear the DTCs? run the car for a bit and see if the issue comes back, if so rescan for codes.

 

I did not reset DTC's or ECU. I unplugged the battery installed the sensor plugged it back in , with battery toke it down the road for 20min and its still bucking...

 

Try having the light/ecu reset by a shop (or if you have your own code reader do it your self) and then repeat, in some cars removing the negitive battery terminal will not reset the ECU effictively, if we can get the codes cleared first and test with a "clean" ecu that will help us determine where to go, and what codes (if any) will help determine the real issue, instead of throwing parts and guesses at the issue...where about are you located?