Hello -

Recently noticed the air conditioning on my 2016 Silverado was blowing cool, but not cold air on warmer days. As a start, I got the R134A (this is what was under the hood on the sticker) AC Pro kit at Auto Zone, and charged it up to about 27-28 PSI on the low pressure line. AC is definitely blowing cooler now, but I did notice that the passenger side vents spat out a few icicles twice shortly after re-charging. I continued to let the vehicle idle and had AC blasting another 5-10 mins, and it didn't happen again. Any thoughts here?

This could also be absolutely nothing or something completely unrelated, but I did notice a small amount of liquid underneath the vehicle towards the passenger side of the front of vehicle. I sat under there for minutes on end while truck was running and saw nothing dripping or leaking at all, and the liquid smelt like regular water / basically no smell.

Your first mistake was putting that JUNK in your cooling syste,. If you want to prevent failure(i have no way to tell you how long or how expensive it will be when it fails from what you did..) you need to now have the entire system evacuated and then the stop leak cleaned from the cold side fitting, then draw a vacuum, see if its leaking, then refill with the proper weight refrigerant only (plus a bit of oil to account for evacuating the system before.)

Hope you didnt sign its early demise. I dont mean to sound cruel but those one shot cans are NOT something you should be using esp on a newer ac system. if you have a leak at that fresh year, there is a problem which likely can be found easily

The evaporator gets cold. It may have got to cold for a moment. The water is from the drain for the evaporator. They sweat.

Was it going up to 28 or down to 28?

What was the ambient temperature at the time?

The "liquid" is just condensed water. It naturally condenses on the evaporator then runs out and drips on the ground.

I'm really surprised EPA allows stores to sell freon to the general public. I have to be 609 certified to even touch it in the shop.

You can buy R-134A just about anywhere, especially Walmart.