on 02 5.9 if i put true duals with high flow cats, do i have to have 2 O2 sensors? i will have an x pipe thought about putting one sensor in the middle of the x. anybody done this?

 

anybody with true duals on newer truck?

 

The upstream O2 sensor is the most important and its input is the info that the ECM uses for adjusting A/F ratios for best burn and to lessen emissions. The downstream O2 sensor is just for monitoring and its info is not used in any adjustments. I do not see any reason that it could not be used the the X pipe. There is a link for a mod that uses a spark plug anti fouling device to move the O2 sensor out of the high flow stream of exhaust to prevent a CEL from appearing. Its in the FAQ section. ..