rental car burnout

The return hose on the 04 WRX is so short I couldn't stick it back in when I tried to install my HKS. I ditched the HKS and put my stock BOV back on. I couldn't stick the stock BOV back on so I just screwed it on and left the plug on the return hose. I drove back from my friends house, to work, and to the dealer about 25 miles total, with my stock BOV venting at 100%, it would idle weird jumping from 1500 rpm to 2000 rpm. The Subaru tech help me put the stock BOV back on. He had to take the intercooler off. I just warmed up my car and I was gassing it. When I let go of gas at 3000k rpm I hear a little whoosh. Is my stock BOV leaking? I know that you can faintly hear the Stock BOV sometimes. Am I just paranoid?