If it's stock, and it's throwing that code, there's a reason, and it's likely a bad o2 sensor. That would cause the CEL even with the resistor. The resistor "mod" only changes the voltage when the temperature is colder than it should be, due to no having a cat heating up the exhaust. The resistor makes the ECU think the o2 sensor is hotter than it is, thus correcting (ish) the different reading. If you're running stock, I'd assume the o2 sensor is bad, or you have another issue where the car is running rich or lean and that's what's throwing off the sensor.