I have a 99 Accord LX V6 automatic. About a year ago I replaced my catalytic converter and both O2 sensors. For the past few months, the check engine light has been coming on for about a week or two and then going off for a week or two. The code each time is P0420. It's getting very annoying and nobody has any idea what the cause may be. I'm hoping someone here can help out. Let me know any other information you may need.

 

did you use a Honda factory cat converter and o2 sensors???
I have seen a lot of non-factory converters work for a few months and than go bad

 

No, they weren't Honda brand but they weren't cheap. I really don't like the idea of "throwing away" over $500

 

We had an accord v6 1999 as a matter of facts ,, we had to warranty 3 non factory cat converter ,, they lasted 3-6 months and code cam back on,. We finally installed a Honda factory converter,,, 2 years later still no code .........
as a matter of facts we had 2 other accords with same issues , try to save our customers money we installed non factory converters ,,, 1, 1998 and another 1999, and since we installed factory cats have not seen them for the same code as well,,we still all sorts of work on all 3 cars .. .We learned our lesson and we will not install non-Honda cats any longer ..We cannot afford to do a job a second time under warranty,, We make no money but most important we cannot afford to have an unhappy customer coming back with the same issue ,,

 

Thanks for the insight. I guess I just hope the light is in the off cycle when I go to trade it in.