k so i took off the exhuast sysytem i had (everything exhuast muffler cat headers) and the o2 sensors i took off the cat and headers are the same i know thats not right cause when i pull the check engine light it pulled up the o2 but when i bought the car the guy told me he had put brand new sensors in so the ones i took off are the white blakc grey colred ones

 

I don't understand what you are trying to ask.

 

Yeah, in English please?

 

cause the o2 sensor's are the white grey and black colored ones i want to know if that one goes in the headers or in the in the cat

 

the colors of the wires has nothing to do with the placement of the sensor. the one that belongs in the cat will have a longer harness (wires) than the one for the header.

 

theyre also the same size but i did notice they have some thing different that one sensor has air holes on the sides and one has them on top

 

now im lost. pics? is this an obd2 car?

 

Civics use more than 1 o2 sensors??? I thought it was only one???
Thats not sarcasm btw. I really dont know.

 

OBD2 Civics use two 02 sensors.

OP needs to put the primary before the cat, if he can figure out which one is which.