i baught this OBX 4-2-1 headers off ebay, and the OBX badge is missing and the inside of the pipes look kinda rough, especialy at the point where the third and fourth pipes combine. And also it looks to have 2 O2 sensors spots. Does my 1991 accord EX have 2 o2 sensors, and do you guys think these headers are fake? Thanks

 

Bad news. OBX is a knock-off themselves, but some of their prodcuts perform fine. Not sure on authenicity of your header (singular) , wish I had more input.