Always scan for codes first, even if no light on dash. Injectors seldom go, 137k is low miles.
The throttle body is an electronic stepper motor design, Hitachi makes the oem unit. They are a wear item and will start to affect idle and codes will be set in ecm. The plastic gears on stepper motor start to bind from wear. RockA has the oem hitachi for a reasonable price, when you actually need to change it.
If it goes to 2000 RPM for 2 or 3 seconds is probably OK, if it last more than 30 seconds I will recommend you to change the intake manifold gasket as those engines with the plastic intake tend to leak.
