Which temp sender did you replace? The one in the driver's side head or the one in the intake manifold? The one in the intake manifold is the one for ECM. The other is for the gauge.
Since it is running bad cold, I doubt it is the 02 since the ECM will be in Open Loop.
Check for any vacuum leaks. EGR solenoid should hold a vacuum (TBI side).
With the air cleaner off, how does the spray pattern look at the injectors?
//2000CAYukon