so my 88 ef d15b1 keeps setting code 1 (o2 sensor) put one in and drive drive drive BLOOP! CEL on again "code 1" went to parts store got another one threw it in...... drive drive drive BLOOP cel on "code 1" checked volts to o2 wire and getting .05v at idle 1.0v at quick rev so o2 is working... any ideas? im soooo lost. ive hurd theres a high fail rate on the header cat but before i run out and buy a header i wanna know what you guys thoughts are

any help will be helpful.... (DUH!! LMAO)

 

Bad cat maybe?

 

Well.. one thing that I am noticing.. is you not mentioning of clearing the code once you changed the part? Did you reset the ECU? If not.. its still stored and will cotinue to throw the code.. doesn't self recognizes the part being changed.. you have to do it.