Hey all, newbie here and I own an Accord because I didn't want to have to work on a car for a few years. Which I haven't had to with this one at least anything other than a thermostat or oil changes....Check engine light just came on with the 420 code. So far, it seems to either be the O2 sensor or the cat for the most part on the posts.
I can hear a little puttering from the muffler area, wondering if this could be the culprit or I also had to remove the hose from the air filter to the intake, so could it be that this isnt' tight enough? Any thoughts?
thanks

 

Exhaust manifold or exhaust pipe connections that leak upstream of the primary O2 sensor can cause P0420. Muffler leaks would not cause this code.

Weak primary O2 sensor could cause this code. It may be cheaper to replace than check.

After addressing above, a new converter may be required. Check for drop-in replacements from quality suppliers.

good luck

 

Thank you. I can do that. Appreciate the help and I'll follow up when I get it fixed.....