If I use an OBD1 LS ECU (P74?) to control my B20 (with an OBD0-OBD1 conversion harness), what is the O2 setup? Is it just one sensor? It is located in the header or the cat?

As a side note, how hard is it to use one of the conversion harnesses? Is it plug and play or is there quite a bit of other wiring knowledge needed to make the project complete?

 

It is one sensor, a 4-wire heated o2. The coversion harness should have the extra wiring necessary to install. If you can find one. I haven't found any one that makes one. I made mine. It works great.

 

in your case you should only have to run one wire from the harness to the engine bay for the heated o2. and a little wiring in the engine bay for injectors and heated o2. I have OBD0-1 conversion harnesses in stock. They sell for $125 shipped

Andy

 

Is the sensor in the header or cat?