Hi there guys i am experiencing a problem on my a4 96 1.8se saloon, hope you can help. I'll warn you this is going to be a long one... anyway. I have a problem with a high pressure build up in my tank which causes my petrol tank/cap to hiss, revs will not settle and also one of the hoses going to the fuel pump has been mooved out of place causing a jet of petrol to be firing out upon ignition because of the pressure going through. What i have now done after replacing the maf with a new audi part, checking for any leaks or loose connections on the fuel lines is to dissconnect the small (charcoal?) filter next to the maf. This has now stopped the irratic revs, hissing of the tank and my fuel lines in the boot connected to the pump now dont leak at all. Is this filter anything to do with regulating the pressure within the fuel system? When i now reconnect it the car splutters like its missfiring. Looking at this info you may now think that i have a simple job to replace the filter but the clips holding the pipes either side seem like they are not easily mooved and are specialist parts so should this be replaced? can some one please shed some light on this as its driving me bonkers and i cant find advice anywhere. What is the technical name for this filter also ?? please help

matty