A/C repair questions

[jsbihn]

Yeah they wanted to replace the whole system.
Even with me getting the parts warrantied, it was still 400 in labor and I was like screw that. I paid 900 a year ago and another 400 this year.

So far since they checked it, it has held steady until yesterday.
Both my daughter and I heard like a pop I think and suddenly the a/c went from frigged cold (steady at 42 degrees according to my mechanical A/C temp probe in the vent) to blowing warm.... then a few seconds later it started to drop down again. It took about a minute to start cooling down but this time it only got to about 46-48, maybe 50. Since then though it has been steady ever since.... just havent been able to get it to the 42 degree mark unless I am driving (and even then it isnt actually getting to 42 completely and all the time).

Any ideas.
I ran some leak stop in there and charged the system... which it didnt appear to need charging (seemed like it was completely full according to the gauge).
So any idea what the pop was and any ideas on why it will cold steady to 46-50 but not to 42 like it did before.
(I dont feel any warm spots in the a/c while it is blowing either)