Monitored & Set Conditions
WARNING: This page is about a different car, the 2003 Dodge Dakota. However, it is still accessible from the selected car via links, so may be relevant.
Catalytic converter efficiency is monitored after engine warms up to 147°F (63.9°C), throttle has been open for 180 seconds, vehicle speed is more than 20 MPH with engine speed at 1200-1700 RPM and Manifold Absolute Pressure (MAP) sensor vacuum is 15-21 in. Hg. DTC will set when catalytic converter efficiency deteriorates and switching rate of downstream oxygen (O2) sensor approaches the switching rate of the upstream O2 sensor. If at any point during the test, the switch ratio reaches a predetermined value, a counter increments by one.