I have a 99 civic si......it runing a b16b block and 1989 b16 head......jdm type-r computer.....unfortunally it won't able to do smog........smog technician told me need to put back a stock computer on it ......ppl told me u just a need to buy a 99 civic si engine harness to put back ur stock computer........can any one tell me what else do i need to change........

 

Oh man, I hate to be the one to brake it to you man, but you won't pass smog with that frankenstein engine. Unless you can somehow fool the smog tech into thinking its just the stock b16. But yeah, you would definately need a 99-00 civic si ecu.