P0053 GMC -

Question

What do I check for with a p0053 code I have checked power going to o2 sensor 11.9 volts ground 11.9 volts and resestance was 6.8 ohms checked all on both bank 1 sensor 1 and bank 2 sensor 1 both upstream sensors seem to be fine as far as the heater anyway did not check the 02 sensor readings them self just the sensor heaters as the p0053 code at auto zone shows it is a heater issue and p0053 is the one and only code to pop up

Answer 1

P0053 H02S Heater resistance sensor Bank 1 Sensor 1

This is going to be the H02S sensor, when the engine is at a cold start this is when the PCM calculates the heater resistance.