Catalytic converter problem on 2000 CAMRY

[Dave S.]

For a CAMRY 2000, 142000 miles, with a PO420 check engine code, my mechanic is looking for a way to determine whether the front or rear catalytic converter is causing the problem. Visual inspection does nor show a difference. Any suggestions? I understand that there is a service bulletin. Where can I find it on the web? I hope it really is a cat problem.

[DOHCammer]

On your Camry, the sensors are only looking at the front converter. You can tell by the positioning of the sensors in the exhaust tract. One sensor is in the top of the exhaust manifold (before converter, measures air fuel ratio), second sensor is just after the front cat which monitors efficiency. The rear cat is just along for the ride and usually get hollowed out on my cars. Assuming you have a 4 cyl, you will need to replace the cat/manifold to get rid of the code.

[SaganGathering]

Originally Posted by DOHCammer

The rear cat is just along for the ride and usually get hollowed out on my cars.

What does that mean?