Watching for a while both went to -30 at their lowest

 

The PCM is pulling fuel pretty significantly. Question becomes..... Why?

The sensor with the most significant affect while in open loop is coolant temp sensor, followed by intake air temp sensor. What do those values look like key on, engine off? (and what is ambient temp?)

 

Iat was reading -40. Both were just replaced. The readings I get seem accurate now, the fuel trim test was immediately after replacing both sensors

 

Yeah, -40 is just wrong. (unless that was the actual temp, however, if it was, I doubt you would be out there working on it. )

Did you reset PCM after changing them? What are they showing now?

 

-40 isn't unheard of around here, but usually not in the middle of august. Both sensors are giving me believeable numbers. I didn't reset the pcm though

 

Give it a shot. See what happens.

 

Reset, no change to the fuel trim. although now I'm getting a p0505. Previously had no CEL

 

Interesting. That's IAC issue. Has the throttle body been cleaned? Original IAC? Check and see if you are getting 12 volts on two wires at the IAC connector. (ignition on, engine off.)

 

Never cleaned the TB. Replaced it about a hundred k miles ago. Original iac from what I know. Could the iac cause it to run lean? Or would that have to be a faulty map / crank sensor at this point?

 

It can cause it to run lean by adding more air, afterall it's a Idle Air Control sensor :b