i have a b16 in my civic and my catalytic converter went bad, so i welded up a piece of piping where the cat was. but my o2 censor got ripped out when my header dropped. so i put it back together and now my check engine light is on and my car doesnt idle right , what should i do . what is wrong .

 

Check why you have a cel!!! Underneath the glovebox you'll see some wires not going to anything and you'll see two wires i beleive brown and black, jump those two and count how many times your cel flashes. Then reask your question

 

your ECU is on limp mode. You are mostlikely throwing a CEL with an O2 code.