P0420 Toyota -2005 camry 4 cyl. Le

Question

Hi, my toyota camry has 3 02 sensor and 2 cats.
I change the back cat and upstream sensor on the manifold.
still the code comes back in few miles. how can I tell if which sensor is bad? I can't keep spending money. Why doesn't it say which sensor or the cat is bad? I really need help! Please

Answer 1

Hi there,

The converter that is bad is the one that is part of the exhaust manifold. The front converter is considered bank 1