Problem with O2 Sensor

Hi everybody.



I'm french ( From Monaco if you want to know), so sorry for my bad english. I come her because the english forum are better than every french forum ( it's my opinion)



So, now, after buy my headers for my E46 Coupe Facelift 320ci From 2005, i bought the O2 sim usw install it with your forum and thank you.



But now i have a problem, my engine light is on after 10 min start :banghead:

and the bmw scanner show me à current default code : Oxygen sensor voltage before catalyst bank 1, open circuit.



But, i change the pre cat, and after cat O2 sensor, i don't find any answer.



I Hope you can help me.



Thank you, and sorry for my english. :pimpin: