OBD code PO420

[venturenot]

PO 420; Catalyst System Efficiency Below Threshold (Bank 1). Anyone have any experience with this code? Is this definitely a catalytic converter problem or could it be something else.

Thank you

[roadrunner2]

Originally Posted by venturenot

PO 420; Catalyst System Efficiency Below Threshold (Bank 1). Anyone have any experience with this code? Is this definitely a catalytic converter problem or could it be something else.

Thank you

Have the post-cat o2 sensor tested before changing the cat, as the electrical connection or the sensor itself may be faulty. This sensor (if working properly) sends a signal to the computer when the cat becomes deficient.

Make sure the engine has been run up to the operating temp before testing the sensor.

The codes only point you in the direction of a possible faulty system.

Year/mileage? Any visible damage to cat?

[venturenot]

It is a 1998 extended van with 153,000. There is no visible damage to converter.

[toni1595]

Here's something to check out, might help you.....http://www.obd-codes.com/p0420


Good luck, Toni.