P1000 is Ford speak for "We are not through running tests to set the monitors" Just a placeholder to say the ECU hasn't done the tests.
The P013C is the real code and the reason for the P1000. The ECM tests the converters and sensors by alternating the fuel mix from rich to lean and back. It compares the time it takes to switch for each test and in this case, it is responding slow. Normally I see this code on vehicles that have had converter codes so someone installed anti fouling extensions to trick the system. The extra time it takes for the exhaust gases to get to the O2 sensor triggers the code or the one that shows the opposite. If everything is stock and it still has the original O2 sensor that is where I would start. Disconnect it and remove it, look for soot or contaminants that block flow. Or just replace it. The one you are looking for is the right side downstream.
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Monday, June 2nd, 2025 AT 9:43 PM