Can someone tell me where is this 21 02s sensor problem (oxygen sensor), upstream or down stream


Ichange the one that isbelow near the catalytic converter :P i wonder where is the other one!

i got to codes 12 and 21 i have a Dodge Stratus 97 2.4 thanks in advanced

 

It's going to be toward the back of the engine - almost inaccessible but you can get to it with a flashlight and some crafty handiwork. Make sure you get the proper removal socket tool. It'll save you tons of headaches.