Chrysler
Type:
    Powertrain - Auxiliary Emission Controls - ISO/SAE Controlled
Description:
    Catalyst Efficiency Fault Conditions
Cause:
    Engine running in closed loop for 3 minutes (throttle open), ECT sensor over 147°F, VSS over 20 mph, engine speed at 1200-1700 rpm, MAP sensor 10-15" Hg, then the PCM detected that the ratio of rich to lean switches from the rear HO2S-12 were near 11 (the ratio should be near 10)

Generic
Type:
    Powertrain - Auxiliary Emission Controls - ISO/SAE Controlled
Description:
    Main Catalyst Efficiency Below Threshold

GM
Type:
    Powertrain - Auxiliary Emission Controls - ISO/SAE Controlled
Description:
    Catalyst System Low Efficiency Conditions
Cause:
    DTC P0100, P0131, P0132, P0134, P0135, P0136, P0138, P0139, P0140, P0141, P0150, P0151, P0152, P0154, P0155, P0156, P0158, P0159, P0160, P0161, P0171, P0172, P0174, P0175, P0300-P0306, P0440, P0442, P0443, P0446, P0455, P1120 or P1220 not set, engine running in closed loop, calculated TWC temperature greater than 716°F, engine load between 8-12%, engine speed from 1400-2200, then the PCM determined that the Bank 2 catalyst had degraded below a calibrated threshold