P0155 and P0135
#22
Checked continuity and everything was good, also got ahold of a Tech II scanner and did a little playing. Found a 0 volt output, and resulting 0 volt input from the computer, leading me to believe that that is where the problem is coming from. I left a message with Nelson Performance, so hopefully it can get straightened out here in the near future.
#28
Just an update, was out today doing a few more checks and jiggling wires, cleared the codes out and so far they have not come back, so who knows, I may have inadvertently fixed something. Hopefully I did, but just wanted to say big thanks for everyone who helped me with this.
#29
Well, went out and fired up the truck the other day and the light came back on. Same heater codes as before (PO135, PO155) so the problem is still there. Think my next step will be to return these o2's and get a set of GM sensors. Otherwise I'm lost as to were the problem is.