at the end of my bottles theres always like 15-20 seconds of air that rush out after all the nitrous is gone even when I freeze the bottle and give it to them

 

my kit had been working fine untill this fill up. ever since its been running very very rich.



and yea i bought a used wet kit..

 

I'm 100% sure that at least part of the tank was filled with air. I plan to take it back to the same shop and have them fill it again tomorrow so i let all that was left in the tank out by removing the connection on the back of the solenoid while doing this it was leaking out a little and i felt it and it didn't freeze my finger like last time when it was full with nitrous..