Hey folks,

I have a 2002 Impala LS 3.8Land the Check Engine light has been on for a few weeks. I plugged in an OBDII reader and it's the P0128 code, again. About 7 months ago I had the exact same problem and had my coolant flushed and the sensor replaced which fixed it until now. I bought the part myself at Schucks and just had the shop put it in, I believe it was a Niehoff. This time I think I'll just do it myself. Anyone else replaced this sensor? Is it a total pain to get to? If I remember right its on the top right of the engine. The car runs fine, but the temp gauge is obviously reading below normal and the heater takes a bit to warm up. I can get the part for like $18 online so I'd rather do this myself if it isn't too much trouble. Any info is appreciated. Thanks!

 

This for the 3.8
Removal Procedure
Notice: Use care when handling the coolant sensor. Damage to the coolant sensor will affect the operation of the fuel control system.

Partially drain the cooling system. Refer to Draining and Filling Cooling System in Engine Cooling.
Remove the thermostat housing. Refer to Thermostat Replacement in Engine Cooling.
Disconnect the ECT sensor electrical connector.

Remove the ECT sensor.
Installation Procedure
Notice: Use care when handling the coolant sensor. Damage to the coolant sensor will affect the operation of the fuel control system.

Notice: Replacement components must be the correct part number for the application. Components requiring the use of the thread locking compound, lubricants, corrosion inhibitors, or sealants are identified in the service procedure. Some replacement components may come with these coatings already applied. Do not use these coatings on components unless specified. These coatings can affect the final torque, which may affect the operation of the component. Use the correct torque specification when installing components in order to avoid damage.

Coat the threads with sealer GM P/N 12346004 (Canadian P/N 10953480) or equivalent.
Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

Install the ECT sensor.
Tighten

Tighten the ECT sensor to 20 N·m (15 lb ft).

Connect the ECT sensor electrical connector.
Install the thermostat housing. Refer to Thermostat Replacement in Engine Cooling.
Fill the cooling system. Refer to Draining and Filling Cooling System in Engine Cooling.