I had code P0420

Question

On my 2003 Honda Accord 2.4L, I replaced the converter and both of sensors and cleared the code. The check engine light stayed off for about few weeks and now it came back on and I cleaned the code again the light stays off for few weeks and it come back on. Any suggestions would be greatly appreciated.
Thanks,
Mark

Answer 1

Hi there,

If you used an aftermarket converter it's possible there is a problem with it already.

Also, try filling up at a different location, and make sure the engine is running good. A poorly running engine can cause the code as well. Also make sure you don't have any exhaust leaks. It can cause the converter code as well.