Cat was cut out of my 06 crv. Mechanic installed new one, w new O2 sensors, but now I have a perpetual Sensor code. Mechanic sez I'll need a new ECM and programming, $$$.
Can it be anything else?

 

Did he hack in a junk aftermarket piece? PO420?

 

It's supposed to be Honda, yes, 0420

 

That is not a sensor code. The cat is not working.

 

If you paid approx 1800-2600 for the cost of the cat only, this would be Honda Oem. Denso makes Honda Oem sensors and aftermarket sensors. Aftermarket sensors may work for a short time but will fail. (Not made the same)