Question

I think the 2002 Tahoe has 4 O2 sensors, do I need to change all 4 and are they all the same sensor or are they different for different areas?

Answer 1

P0430 Catalsyt below threshold Bank 2

This code is for the catalytic convertor, being non effective in controlling emission. The code condition is for Bank 2. This vehicle has 2 Banks , Bank 1 is where cylinder 1 is located and Bank 2 is the opposite of where Bank 1 is located at. You have a total of 4 02 sensor the front is the engine management sensor, the rear is the catalytic monitor sensor. If you purchase 02 sensor the front will be different than the rear, and a total of 4 02 sensor.

Here is a Chevy vehicle there are 2 catalytic convertors . One is Bank 1 and the other is Bank 2, In the Back of the catalytic is the downstream 02 sensor which is to monitor the catalytic convertor for efficiency, the front manages the engine performance. With your code you would just need a catalytic convertor.