Conditions for Running the DTC

WARNING: This page is about a different car, the 2008 Cadillac CTS. However, it is still accessible from the selected car via links, so may be relevant.

Before the ECM can report DTC P0420 or P0430 failed, DTCs P0030, P0031, P0032, P0036, P0037, P0038, P0050, P0051, P0052, P0056, P0057, P0058, P0100, P0101, P0102, P0103, P0121, P0122, P0123, P0131, P0132, P0133, P0135, P0137, P0138, P0140, P0141, P0151, P0152, P0153, P0155, P0157, P0158, P0160, P0161, P0221, P0222, P0223, P0335, P0336, P0338, P2096, P2097, P2098, P2099, P2195, P2196, P2197, P2198, P2232, P2235, P2237, P2240, P2243, P2247, P2251, P2254, P2270, P2271, P2272, P2273, P2297, P2298, P2626, and P2629 must run and pass.
DTC P0010, P0011, P0013, P0014, P0020, P0021, P0023, P0024, P0030, P0031, P0032, P0050, P0051, P0052, P0100, P0101, P0102, P0103, P0116, P0117, P0118, P0119, P0121, P0122, P0123, P0125, P0130, P0131, P0132, P0133, P0135, P0137, P0138, P0140, P0141, P0150, P0151, P0152, P0153, P0155, P0157, P0158, P0160, P0161, P0221, P0222, P0223, P0300, P0301-P0306, P0443, P0455, P0458, P0459, P0496, P2088, P2089, P2090, P2091, P2092, P2093, P2094, P2095, P2096, P2097, P2098, P2099, P2100, P2101, P2107, P2119, P2122, P2123, P2127, P2128, P2138, P2176, P2177, P2178, P2179, P2180, P2187, P2188, P2189, P2190, P2232, P2235, P2270, P2271, P2272, or P2273 is not set.
The engine speed is 1,080-3,000 RPM, or 1,040-2,360 RPM for LLT.
The engine load is 13-50 percent, or 17-60 percent for LLT.
The air flow into the engine is between 4-19 g/s and steady, 4-21 g/s for LLT.
The engine intake air temperature (IAT) is greater than -30°C (-22°F).
The HO2S 2 is at operating temperature for greater than a range of 160-300 seconds, or 140-210 seconds for LLT.
The engine is operating in Closed Loop.
The calculated TWC temperature is between 480-750°C (896-1,382°F) and steady.
The difference between the expected TWC temperature and the calculated TWC temperature is less than 40°C (72°F).
The difference between the expected exhaust gas mass flow and the calculated exhaust gas mass flow is less than 11 g/s.
The above conditions exist for approximately 17 minutes.
DTCs P0420 and P0430 run once a drive cycle. The ECM will attempt to run this diagnostic up to 4 times per drive cycle, 3 times per drive cycle for LLT.