I just gotten this code, and have been searching the forums about it. I have 05 revup with berks HFC, 5/16 spacer, mrev2, jwt popcharger, z tube, and tdx2. When I got my berks HFC I got a retune and did not have an SES light for about 5 months. How can I fix this and does having these codes do any harm?

 

those are your upstream sensors. they control the air fuel mixture. do you get both codes at the same time? if its one or the other, i would switch the sensors to the opposite side and see if the code moves with the sensor. If it does change the faulty sensor. if it doesnt you will have to dig a little deeper and check that there are no leaks on the intake side of the motor, your mass air flow sensor is clean, injectors are good, fuel pressure is good, or could be just both sensors are bad.

 

I got both codes at the same time and do you have the parts number or a link for the upstream up stream sensor