I have a 2003 WRX that is stock except for an aftermarket up-pipe that was installed when I bought the car. I already did the resistor mod to get rid of the CEL it would throw but now I have it again. Could it be possible for the resistor to be bad or am I thinking of a different code? I'm honestly just looking for information on what should be done about these and what others did to fix it, Thanks.
EDIT: Also, the car seems to run fine since the CEL came on but I haven't driven it hard to be sure. My car has 97,000 miles on it