ok i bought a 2002 f4i and it has a brand new exhaust i noticed it has the bung hole for a o2 sensor but i cant find one is it true that this year didnt come with one

 

only california models had them

 

Correct. 01-05 California models only, and all 06 models have the O2 sensor. You can usually find a bolt that will thread into the spot to close the hole, that's what I have on mine. I got it from a guy on here who used to custom make exhausts, and he kinda fell off the grid. BUT I bet one of the big manufacturers have something.