2003 Honda Civic Hybrid Q&A
2003 Honda Civic Hybrid Question: How do I know which cat is bad?
I have a 2003 HHybrid and I can smell the cat and getting the P1420 code. How do I know which cat needs to be replaced? - Visitor
You need to contact to a Honda dealership with your VIN#. There is a known problem about the P1420 DTC. It could be caused by a wrong software in the ECM, so a simple software upgrade might fix this problem. If it caused by software error, catalytic converter replacement won't fix it. You will spend $$$ on a new cat, and the code will come back. The dealer will be able to tell if the "Service Campaign" can be applied to your car and get free software upgrade. Zee - ZeeTech