I have 2001 Audi TT with check engine code P1136. I found 1 vaccines hose leak and replaced. Cleared code but same code came back. Also replaced PCV and another valve with no luck. When I start car up after it sits couple days I hear an air leak but goes away after about 1 minute but can’t find it by feeling around. Did a smoke test and don’t see any leaks. Thought about replacing the maf sensor but I do hear that leak. Any ideas on what could be causing a leaking sound and go away? Getting really frustrated, anyone have any ideas? Would really appreciate any help! Thanks Bill