Engine Cooling problem
2002 Chevy Impala 6 cyl Front Wheel Drive Automatic 73000 miles
PO128 appeared on my car while driving down the highway. I cleared the code with my MemoScanner (no freeze codes) and have driven the car 2-300 miles without any code coming on. Yesterday I drove the car on a 100 mile trip and checked the coolant operating temperature with my scanner and it was 88Celsius/190F. It indicates cool but it appears it's running at normal operating temperature. Does this mean the temperature sensor is bad?