Toyota Repair: too much refrigerant in AC?, r 134a, oil additives

Question
Today I added 2 cans of R-134a to my 1999 Toyota Camry with 205K miles.  The air coming out of the vents was 85 degrees before adding the cans and the compressor didn't even come on.  Now the compressor comes on and the vent temp is 50 degrees.  The pressure gauge on the refill system was in the green (good) range even after the 2nd can.  My question is: Should the compressor stay on or cycle on and off?  Mine is staying on.  If a second question is OK, I'm wondering if I should have used refrigerant with the oil additives rather than plain refrigerant?  Thank you.

Answer
The compressor should cycle on/off, the capacity of the system is (28.22 ± 1.76 oz.)which translates into 1.76 lbs +/- 1.76oz. If the system was completely empty you're very close with 2lbs so I don't think it's overcharged, if it was you would know because the compressor would shut off completely. There is also a sight glass near the receiver drier unit on the high side, with the a/c running check for bubbles if there are no bubbles it should be ok.