i have an '88 b16a motor that im going to put into my '91 Si and i already have a skunk2 obd-1 p28 ecu that i had been using on my '99 Si with the obd-2 to 1 harness... is there such a harness for obd-1 to 0?

 

Your subject & last question dont make sense, but ya there is such thing as OBD0-to-OBD1 conversion. Its much easier than going OBD2-to-OBD1

 

and, like the question in the topic says, how?

 

conversion harness. plugs inbetween your ecu plugs and the obd1 ecu it self. have to switch to an obd1 dizzy.

 

If you don't want to search for the harness I have spliced all of the connections before, it is actually quite easy... BTW you will need a new distributor and if you are going to use the stock injectors you will need a resistor box. As well as a 4 wire O2 sensor and the corresponding exhaust pieces that it fits into. I don't know which ones that is in the Civic, for my Integra all I had to change was the exhaust manifold and downpipe.