Both these codes showed up today. Hooked up my code reader and tried running a live diagnostic on it. I'm trying to figure out if i need new 02 sensors or new cats. Any help would be greatly appreciated.
So I took it to Toyota, they said I needed 2 new manifold cats. I was wondering what would cause both upstream cats to go bad within a week of each other? Toyota said it might be due to putting autolite plugs in my vehicle. But I put those in after the p0430 code was thrown. Then 3 days later the p0420 code was thrown. Any ideas?
