Hi there, I have had the two back boxes deleted on my A5 3.0 V6 TDI. There is a loud hissing now from the exhaust when idling and then all of a sudden it can get louder. It is a bit like a hair dryer noise! Sounds great when I put my toe down though! Any ideas what this could be please?

Thanks.

Hi Gordon....welcome to the Forum!

It sounds like there is an exhaust leak, especially as the system has been altered recently....check by getting a friend/wife/neighbour to put a rag over tailpipe(s) to seal the exhaust and you'll be able to hear where it is escaping from.

Alternatively, it could be a split in one of the intercooler hoses that's making the noise.

Let us know how you get on with it

Cheers   Trevor