Hi All,

I have 2007 Honda Accord VP 4cly manual with a check engine light that comes on for a few days and then turns of for a couple weeks. When the light goes on, I went to Autozone to get it checked and they say its the P0420 code "catalytic converter inefficency". I even had the dealer do a diagnostic and they said the samething. Although I am not convinced. The car does not idle rough at all. And notice not performance degration. In fact, I even cleaned my throttle body, air mass flow sensor and injectors and seen a performance boost.

• Why would the check engine light go off?
• While the O2 sensors have their own codes, could it really be an O2 sensor malfunction causing a faulty catalytic converter code?
• Also I use premium (93 octane) gas. Can this be an issue?

Thanks!

 

The code does point to the converter. I would inspect the exhaust system for any leaks in the system as this can cause the readings between the two O2's to be out of spec.