2003 Honda Accord LX 2.4 liter. I had an O2 sensor heater circuit engine ligjt for quite some time. I finally replaced the O2 sensor, and now I’m getting a P0420 engine light code (low catalytic efficiency) after a drive cycle. Is there a chance that my new Walker brand, O’Reilly auto parts O2 sensor is bad, or is it more likely my catalytic converter has failed?
Well it’s a Honda, they don’t like most aftermarket sensors. Because it was a heater code I would suggest an OE sensor first. It’s possible the cat went bad while the light was on but if the heater code was the only code I would suspect it doesn’t like the sensor.
That’s what I’m hoping for, but I’ve been reading otherwise.