I've been having problems staying in closed loop at idle and even difficulty getting there while driving lately on my 350 TBI, so I've decided to go with a heated O2 sensor. I've read just about all the threads on here that say to tap into the fuel pump relay, however I don't see a pink/black wire going into it. In my wire loom in that area (drivers side firewall) I have at least three separate pink/black wires. My question is if all of these wires are created equal, i.e. are 12V IGN wires?

I'm planning to take care of this tomorrow so any help is greatly appreciated.

 

You want the wire that is turned on by the relay ( going to the pump) ;
not the wire that turns the relay on

 

So according to that diagram, that would be the tan/white wire?