Spilled liquid down shifter n console and need to take console apart to clean before it dries

Pull the shifter and clean it. Spray the shift lock solenoid and plug off with brake clean and blow it dry. Lube the moving parts with dry graphite or lithium grease. Not the solenoid.

The shift console has nothing to do with the emissions limp mode.
There is a solenoid to disable the shifter from being able to be moved out of park, but that is in order to ensure you press down on the brake. Don't know what could be wrong except that you might have blown a fuse that powers the transmission.

If by won't change gears you mean that the shifter will not come out of park. The manual will not help you in that situation. The shifter assembly will have to be replaced especially if a liquid was spilled directly on it. There is a shifter override feature on the shifter if you remove the shifter wood trim that sits around the shifter. There is a black lever on that can be pushed down while pulling the shifter knob out of park.

Is it a center console shifter?(this model came out after i left the car business).If so,then did you spill a sugary drink on it?(I replaced the shifter cover on a Firebird 3 times on the same car because the owner left a McDonalds cup (waxed paper type) in the cupholder 3 times).The sugar glues the plastic parts together,which takes a lot of force to break it loose.If you think this could be it,take a washcloth with hot water on it and wipe it down,while changing gears,to clean it out.(in extreme cases,you might have to take it apart and clean the parts).

you will probably have to take it apart and thouroughly clean it. If upon cleaning it you notice something wrong, let me know and I will walk you through a repair if you need it. Hope this helps.

Try spraying pb blaster or similar on the shifter cable linkage on top of the transmission.
If that doesnt help u may need to take apart the center console to access the shifter assembly
it may be gummed up with pop, coffee etc begine spilled down in the cupholder shifter area .

Happened to me, and I got stuck in a parking lot. In my case, I had to take apart the entire console to physically look at the shifter... there is a solenoid that should engage when you press the button on the shifter in order to shift out of park. For some reason, mine was rusted and would not move. I simply took it apart, cleaned it, sprayed it with lubricating & penetrating oil, and worked it by hand until it moved freely.
Solved the problem for good - it's now been 3 years since then. I also found that it may have been triggered by someone spilling a drink around the shifter from those terrible cup holders. That and I also found a very slow leak coming from the sunroof drainage hose that would leak from the overhead lights straight down to the shifter.... thanks Pontiac!
I hope this works for you... when I spoke with a dealer, it was supposedly upwards of a $600 repair to replace that entire assembly/solenoid.

there is no reset for shift interlock if you turn the key on and you press the brake down and hold it for a minuite or so WITHOUT touching the shift lever yet and it comes out of park, then the problem is most likly soda or ther liquids that have been spilled in the shifter area over the years and caused the shift silond to become sticky .would need to be cleaned

did you get a solution for this. I spilled my son's milk in it.

If you have spilled any coke or coffee on shifter it will cause the shift lock actuator to stick if you have floor shifter. You will have to remove center console to clean. If nothing has been spilled shift lock actuator needs to be replaced.