I seen the diagram also you posted, but I was still confused on which is should be. I'm thinking single wire since it's a dually full size?
That's a pretty safe bet given that >8600 GVWR trucks were usually forced to meet
a relaxed emissions standard. (At least back then, things have since tightened?)
Going back to that diagram, if it was me I would look to see whether or not there's
already a tan wire at PCM pin A12? Assuming it hasn't been hacked by a PO in this
area, no tan wire = factory single wire. (matching >8600 rule of thumb for Federal
emissions. Cali emissions? YMMV)
Or, the tan wire *is* present, which would be the telltale hint that originally
the 3-wire HO2S were part of the original build.
Take a close look at your PCM, and let us know what you find.
(The PCM connector pinouts are definitely in the FSM, no guessing
required.)
Best of luck with the hunt. Glad you are focused on getting your truck correct
instead of how do I workaround/mickey-mouse my setup? :0)
Cheers --
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