Catalyst Diagnostic Hardware

Catalysts and Front Pipes
As you have seen, all V6 engines receive two new catalysts, front pipes and accompanying changes to the exhaust system. This change allows the two cylinder banks to operate a bit more independently of each other than if we had a single catalyst and post-catalyst sensor.

Four Wire Oxygen Sensors
All 1996 oxygen sensors (both pre and post catalyst) are of the four wire variety instead of the three wire preheated type we have used for the last ten years. The additional wire provides a ground at the ECM for the sensor itself instead of relying on the condition of the sensor threads, exhaust pipe, etc.. as we do on the older versions. Pre- and post catalyst sensors are significantly different, connectors are indexed to prevent the crossed signals which would result from hooking the output from sensor 1 to the ECM input for sensor 2.