I didn't think my 2008 was blowing cold enough air so I decided to add some R134. Picked up a gauge, watched a couple you-tube videos and it looked pretty easy. Seemed like every time I squeezed the trigger to add more R134 the pressure went down!!!!! Everything was connected properly (no leaks), AC was on full blast and the compressor was running. I now only have cold air at idle. Not sure if I should give it another go or not. Any ideas?????