Is there any need of extra wires to the engine bay and can the ecu converted harness be plug n play?

 

b18b is just plug and play, just remember to use the 1 wire o2 sensor and i use the b18a axels and tranny. you will have to extend the fan relay sensor, found on your coolant pipe. b18a has the 2 pin sender on the back of the block, the obd1 b18b has it close to the thermostat.