Ok i have a few questions about the conversion. I need to buy a conversion harness right? If not it will not plug. (i have a 98 civic EX) Also, what do i lose by converting down? This may be a stupid noob question (im new to the ECU's) but the OBD1 are from earlier models right, so by pluging those in would i lose any extras in my car that the older model cars ddnt have? Sorry if these are stupid questions, but i just want to know exactly what happens if i buy these (i intend of having mine tuboed by early april at the lastest)

 

You won't lose anythinb but a couple sensors that you don't need anyway, unless of course you need to pass emmisions.