Quote
There is nothing electrical tied in with your mechanical speedometer


earlier this evening I linked to a thread from a few years back about 2.6 idle issues & an explicit nugget from Mr. Marcucci jumped out at me regarding this:

Quote
- Speed Sensor: this is actually your speedometer. The cable goes from the tranny to the speedo, the speedo then turns it into an electrical impulse for the ECU. ....controls the fuel injectors- the system cuts fuel when you are decelerating for economy.

thread

Isuzu refers to it as the CSS - Car Speed Sensor. if the sensor itself was conking out it would possibly throw a code 63. you can check it at the connector behind the speedo & it should alternately indicate continuity & open circuit as the cable rotates(4 pulses/rev).

by chance have you ever gotten a code 44 over the course of your o2 problem?

2.6 Trooper
2.0 Impulse Turbo