make sure the engine, wiring loom & ECU are from the same car.
clean & clear the engine open the hose pipes and check for draining liquid.
it shall not be foamy nor milky open the thermostat housing to see the condition of flange. any sludge, foam or milky residue .. engine is half dead due to overheating head gaskit kaput engine discarded scrapped.
if draining liquid is clean as running water thermostat flange is clear clean of any trace of rust, milky layers or colored residue its all good.
test the engine & wiring outside the car. JDM vehicle engine have cat converter & O2 sensor. all sensors shall be working and wired properly.
no twisting no nitto tapping. soldering & heat shrink ( heat shelink toob ) tubes shall be used to insulate & isolate the wire cuts.