O2 sensor ??

[Chuck L.]

I posted on FSC, and decided to add it here, too. Thot I may speed up the "learning process".:grin:
"Am still working on the 7.4 Vortec, in the 2000 3/4, and have a question regarding sensors.
The truck has no cat[s], and a custom exhaust system on it.
There are 2 O2 sensors still in the head pipes, but no sign of the rears.
From what I've been able to read on other posts, there were originally 4 sensors.
The ? is: were all 2000 7.4 trucks equipped w/ 4 sensors?
I have looked at the tune file w/ EFILIVE, and see that the rear sensors, along w/ other smog related items, are shown as "not reported".
I read this post, and found I have a software version that does not have the pid[s] I need.:doh2:
http://forum.efilive.com/showthread.php?t=4417

[I get no fault codes, nor have I found empty wiring plugs/sims.]
Maybe, I'm looking for something that doesn't exsist?
Can someone e me a stock tune file that I can use w/EFILIVE??
BTW, DFE1 and I are going to update my software tomorrow!!:grin:
NE help is appreciated!:cheers:

[RonSS]

Hello, Mitchell shows rear O2’s only on California trucks for a Big Block ¾ ton 2000. Not sure how the rest of the country got away without rears but I’d bet your truck never had any rear sensors….

[joecar]

What Ron said.

GM eSI shows 2 wire diagrams for 2000 GMC C 2WD 7.4L:
RPO NF2 "Federal Emissions" -> 2 sensors
RPO NB6 "California Emissions" -> 4 sensors

[Chuck L.]

Thanks!