My 1997 Chevy Express 3500 with the 5.7L needs a new engine coolant temperature sensor (throwing P0118 OBD code). I bought a new sensor with an oval plug which looks like these:



I went to replace the sensor and found that the harness appears to be modified with a wire grounded to a bolt above the ECT sensor. In addition to this the old ECT sensor appears to be broken and barely plugged in as well as the harness plug being a totally different shape (round not oval) than the new replacement sensor? Did I buy the wrong sensor or is there something wrong with my harness? See Images below: