As the title says, the Mach won't pass the emission part of inspection. Earlier, I had a check engine light due to bank 2 sensor 2 stuck on lean and a high voltage reading to the same o2 sensor, so I replaced both rear o2 sensors. I drove it around, the CEL cleared, but it still won't pass. They're saying the monitors still aren't ready yet and now the catalytic converters "won't work," which I have newly installed American Racing Headers. I do smell gas when the car is running, but I'm all out of ideas. The CEL is still gone. Is it possible that the PCM or ecu is going bad?