Hi, My little boxster is currently off the road. When I first fire it up, it has a load bang / pop (like a balloon bursting) noise coming from the air filter housing. it idles really really badly, once it warms up it seams to be okay. only code in the system is for 02 sensor bank 1 after cat, says system too rich. Only comes on when the car is warm. so I'm guessing it's sucking in too much air. don't a smoke test, little bit from the rubber seal at the bottom of the AOS but that's it (it's a new one). I'm suspecting the valve in the intake manifold isn't working so there is too much air at idle. anyone got any ideas, im not sure how the whole vacuum system/ canister works. cheers​​​​​​​michael​​​​​​​