So I have to replace the downstream O2 sensors quite often due to the heater in the sensor going bad. I'm getting quote tired of doing this, as the sensor part works just fine. I want to emulate the heater circuit. I know that the heater circuit shows 5.5ohms on brand new sensors. What else is needed to complete the circuit other than a 20Watt 5ohm resistor? Help will be extremely appreciated. Thank you.

 

Why not just find out what is causing the heaters to fail so often? They should easily last 10+ years. If youre replacing them more often than that,you have an underlying issue.

Besides,the heater circuit is dynamic,its values vary in response to PCM commands,you cant replicate it.

 

He's right, the ECU will throw a check engine light and code if:

• There is a short circuit
• There is an open circuit
• OR If there is excessive current draw in the circuit

So: It not only monitors for open or short circuits but it's amperage or current draw is monitored. You would need to design an electronic module with multiple components that would respond with the correct resistance values in corordinance with the ECU's applied voltage AND operate with the correct current values in coordinance with the ECU applied voltage/current. Your talking about spending the same $ as it would take to replace the sensor just to begin designing an electronic module. Since the oxygen sensor's heater circuit responds to different voltages & current, you'd need all kinds of electronic parts like transistors, capacitors & resistors. It's not worth it, just replace the sensor. Use a genuine Honda OEM sensor or a quality replacement like BOSCH.