this is it im furious i just spent 5 hours fabbing the postcat o2 sensor to fit the header and it is not going into the hole do i really have to use both o2 sensors for my car or is 1 enough?
what will happen if i dont use the second down from header o2 sensor will it give me trouble?????

 

Yes, if you have to pass emissions. The second O2 sensor is mostly used to check if the catalytic converter is dead.

 

ok so what do you mean by this rofl
will it cause problems with my car?
pass emissions how????

 

If you don't have emissions you don't need it. There will probably be a check engine light though. And you won't know when your catalytic converter has stopped removing toxic gases if you care about air pollution.

 

oh.......lol well cel is already on for another pointless error code i think its p1406 evap system error codes
arent they just tree hugger codes??? lol do i really have to worry about my car polluting with the billion other cars????? XD