Engine Coolant Temperature Sensor, Water Temperature Sensor, Auto Replacement Coolant Temperature Sensors, 37870-PLC-004 37870-PNA-003 Cooling Fan Switch Coolant Temp Sensor for Honda Civic

I procured this temperature sensor as part of diagnosing a heating issue with my 2004 Civic DX. You can see in my photos that this replacement sensor has white plastic parts, and the original has black plastic, but at first blush they seem otherwise identical. I used a resistance test to confirm that the new sensor was in the ballpark of the old one. The original sensor measured 2.7 kOhms, and the new one measured 3.8 kOhms at about 40°F. The new sensor was also measured at 7.2 kOhms when stuck in a snow bank, so I was confident that it was changing resistance with temperature. The only tools I needed were a 17mm socket and ratchet. This sensor came with a new o ring, and it was easy to install. I recommend flushing or topping off your coolant after installation, because there will be air trapped in the cooling system. The only problem I ran into is that the retaining clip in the electrical connector was slightly wider than the OEM part, and prevented the electrical harness from completely seating into the connector. I narrowed it slightly with a razor, as shown in the last picture, and then I heard the solid click I was expecting. I have put about 150 miles on my car since installation, and no problems so far. It seems like the heater is working somewhat better with this sensor.

Did not fit. I could not tell you if it works.