Code Enable Criteria

For DTC to run, the following conditions must be met:

DTCs P0101, P0102, P0103, P0107, P0108, P0112, P0113, P0117, P0118, P0121, P0122, P0123, P0125, P0171, P0172, P0174, P0175, P0200, P0300, P0325, P0327, P0332, P0335, P0336, P0341, P0342, P0343, P0351-P0358, P0410, P0412, P0418, P0440, P0442, P0443, P0446, P0449 , P0500, P0502, P0506, P0507, P0704, P0801, P0803, P1258, P1336, P1415, P1416, and P1441 are not set.
Engine is operating for more than 450 seconds.
ECT is 167°F (75°C)-248°F (120°C).
IAT is 64°F (-18°C)-176°F (80°C).
On manual transmission models, since end of last idle test, engine speed is more than 1000 RPM for a minimum of 37 seconds.
On automatic transmission models, since end of last idle test, engine speed is more than 1000 RPM for a minimum of 44 seconds.
BARO is more than 74 kPa.
Fuel system is operating in closed loop.

When conditions for running this DTC are met, the following conditions occur:

PCM captures current rear HO2S rich-to-lean status.
Air/fuel ratio transitions from rich to lean, or from lean to rich, depending on capture rear HO2S rich-to-lean status.
Air/fuel ratio transitions a second time opposite the first air/fuel ratio transition.
PCM captures response time of front and rear heated oxygen sensors when air/fuel ratio transitions occurred. Response time is time during which HO2S goes from less than 300 mV to greater than 600 mV, and from 600 mV to less than 300 mV.
PCM measures time for rear HO2S voltage to cross a reference rich-to-lean threshold, minus the time for front HO2S voltage to cross same rich-to-lean threshold. Time difference from the front and rear HO2S is oxygen storage capacity of catalyst.

DTC will set when PCM determines oxygen storage capability of catalytic converter has degraded less than a calibrated threshold.