i did a diagnostic test on my 1999 neon and got code 21

21 02 sensor problem (oxygen sensor), upstream or down stream


how do i get this fixed? do i just replace the o2 sensors?

 

I'd replace both O2 sensors and reset the computer (PCM). There are two ways to do this.

Remove the 20amp fuse under the hood labeled FUEL PUMP for 30 minutes to an hour or remove the negative battery cable for the same amount of time.