2013 Honda Accord EX 4 cyl 155K miles - check engine light keeps coming on then off then on again. The code is the infamous P0420 code. I cannot believe it is the catalytic converter...could be but I have my doubts. I have replaced the gas cap, the downstream O2 sensor and about to replace the upstream O2 sensor. Has anyone else had this problem? Is there a reliable (non-harmful) catalytic converter cleaner available?

 

It needs a cat.

 

The truth often hurts! Thanks for your feedback.

 

Follow up...you were correct...replaced CC and no more light (knock on wood)