I'm not a pro with A/C but I really think 1 can is too much. The cabin air filter is not your problem here, it's just a filter.
Just to clear something up; Does the engine surge (idle up and down) or is it just a higher idle? The idle is supposed to go up a bit when the A/C is turned on. Mine goes from 600 to 1000 ( too much) no matter what gear it's in. But I think my compressor is shot. Have you checked for any A/C codes? http://www.lexls.com/tutorials/air/accodes.html

 

The idle will be around 600 and the car will surge forward for a second, almost as if you are putting the car into gear when your RPM is around 1500 or so. I have also noticed the AC starts out pretty cold and after a minute or so becomes warm.

i tried to check AC codes but I am unable to read to the display when it is cold. I was able to enter the diagnostic screen but i couldnt fully read the code. Once the LCD heats up i should be able to check the codes. From what i could read there was a code that looked like 21 or 31 but cannot be sure yet.

I will post once I have the code(s).