I have a 1998 Chevy Venture. The service engine light has been on for about two months. I took the van to Auto Zone and they connected a scanner to the OBDII connector. The scanner showed a code P0420 which seems to be either a bad catalytic converter or bad o2 sensor(s). Can someone give me some instructions on how to check the oxygen sensors? I can replace the rear sensor, but the sensor near the engine looks like a bad situation however. No room to work, not sure how to get to it to even check it, let alone replace it. But at $67.00 I want to know they are bad before I buy new sensors. If they can be checked and are good, I will take the van to get a new converter.
Thanks, Terry