2004 Honda Pilot DTC 41-2 and DTC 65-2: HO2 Sensor B2 S1 and S2 Heater Circuit Malfunctions Explained
My 2004 Honda Pilot is showing DTC 41-2 (HO2 Sensor B2 S1 Heater Circuit Malfunction) and DTC 65-2 (HO2 Sensor S2 Heater Circuit Malfunction). I've noticed the vehicle experiences a drop in engine pressure during highway driving. What could be causing this connection between the oxygen sensor heater circuit faults and the loss of engine compression?
The loss of compression might not be directly caused by the HO2 sensor heater circuit issues, but it could indicate a deeper problem such as a failing cylinder or intake manifold leak. It's important to diagnose separately—first check for misfires and then inspect engine compression with a compression tester.