Typically, they’ll idle ok and drive normal under a light load.

Loss of Power– It is a really strange feeling to drive a vehicle with a catalytic converter that is going out.

Mileage- May or may not suffer depending on how much or if the catalytic converter is clogged.

Often, when it is only the oxygen sensor is the issue, you’ll feel no symptoms at all.

Here are the typical symptoms that something is wrong when you have code P0430. For most people the first sign that anything is wrong at all is the service engine soon light coming on.

There aren’t usually any drivability issues associated with P0430. When the readings from the upstream and downstream oxygen sensors show similar readings, it means these exhaust isn’t being scrubbed and the vehicle will throw the service engine soon light (P0430). The computer wants to see that the catalytic converter has scrubbed exhaust emissions. The upstream and downstream oxygen sensors should show different readings. P0430 means that the Oxygen sensor downstream of the catalytic converter is registering an improper reading. Among the many jobs that oxygen sensors have is they have to measure the emissions levels coming in and out of the converter. Your Expedition has at least two oxygen sensors, one before and after the catalytic converter. It doesn’t matter which model you have, this OBDII code has the same meaning for all of them (1996 models and newer). This code number references a number that is given to you when you plug your Ford Expedition into a OBDII scanner. One of the most common trouble codes with all Ford vehicles is the P0430. P0430: Catalyst System Efficiency → Below Threshold → Bank 2

In the Expedition, OBDII P0430 is often caused by a bad oxygen sensor, but there can be other causes as well. This page is meant to help you troubleshoot the Ford Expedition P0430 trouble code.

Ford engine codes p430