I bought a 96 F150 4x4 with a 5L a while ago, and the previous owner had dual straight piped the exhaust and did not properly deal with the rear O2 sensor (relocated to the cross pipe between the dual exhaust). As a result, the rear O2 sensor is reading lean. I spoke with a couple exhaust shops about options, and was told by one shop owner that relocating the sensor to one of the pipes ahead of the cross pipe may solve my problems. I was looking into this since it seems to be a good way to start out considering the low cost, and was wondering how the distance in or out of the exhaust stream would affect the sensor readout. Does anyone know how to figure this out? I'm also wondering if anyone else knows of other potential solutions such as sensor simulators that would get my truck reading the correct value and turn out my check engine light? Thanks

 

I also want to move my o2 sensors. Maybe someone will comment. I live in Florida and do not have a sniffer test. Or an inspection for that matter.