I have replaced both oxygen sensors at the catylitic converter on my 2002 Honda CRV. I still get the P1167 Primary HO2S (NO.1) Heater System code when I test the vehicle. Are there other sensors I have to replace? Where are they located? Thanks

Reset the ECM and see if the problem goes away. You may be able to do this by disconnecting the negative battery cable for 10 seconds.

Hopefully, you used Denso oxygen sensors and not Bosch.