P0420 and P0446 Codes

Hi,

I have a Camry 2000 V6. I keep good care on this car. However, about a month ago a problem started to develop. Only when the car is warmed up. When driving with the RPM between 1200 and 2000 the car is sluggish and the RPM drops for a split second. After a day or so the check engine light came on. I reset the onboard computer and the light went off but the RPM problem was still there. So I took it to Toyota a week later. They ran their check and nothing came up. The RPM problem is still there and a week after it was at Toyota the check engine light came on again. So I checked the Codes P0420 and P0460. Are they related and if so what could be my problem? If I clear these codes the engine light will go off for a while but the RPM problem is still there. I need to find out what it is so I can fix it.
Thanks for your help.

Have you replaced the fuel filter?

Hi,

I forgot to add that I have replaced the fuel filter because I thought that might be the problem. And I have also replaced the spark plugs because I thought I might have had a bad plug.

Thanks for vewing this post.

P0420 Catalyst System Efficiency Below Threshold (Bank 1)

I think is a EGR Valve stuck partially open. Killing the combustion and cooling the exhaust gases.


P0446 Evaporative Emission Control System Vent Control Circuit Malfunction

Is the gas cap worn? I am wondering if the Evaporation problem is due to a worn out gas cap. That is an easy test. Check for a worn or loose vacuum hose, but that will give you a higher idle, you never know, but does not hurt to check.