Rich Idle with fan running lean with out

[joecar]

Figured it out. 02 Camaro tune only requires one ground to see park and neutral, where as the truck OS requires two (pin 32 and pin 34). That is why I would see park/neutral in one OS and not the other. As for the for the fuel trims, one o2 was hanging out at .435 to .465 volts. That tells the PCM that the o2 is bad and wont start fuel trims. All fixed and working.
Thanks

Thanks for posting back.

Did the GM truck wiring diagram show 2 grounds for the P/N switch...?

How was this fixed...?

[kostelacd69]

The truck diagram shows the two pins doing different things but after looking at the truck and camaro diagrams figured out that both pins could take a ground. Decided to share the same ground from the pnp switch and then it worked.

[kostelacd69]

As far as fuel trims I replaced the week old o2's with new ones. Fuel trims turned right on.