Well, having had the same problem and freed the breather, the interior of my car now stinks like a giant car has urinated all over it. Is there any way to get rid of this wonderful smell or is it the case that I have to rip out all the foam insulation affected?

EP stinks. Never found much that would cover the smell, so you'll need to remove as much as possible - I'd think something industrial could be involved, or just replacing the foam and carpet from a scrapper.

i had this problem ages ago before i cleared the breather and my foam was well saturated. I removed it all, washed it in detergent several times, and cleaned the whole surrounding area with a special "citrus degreasing agent" that i grabbed from work (cinema projectionist - we use it to clean the internals of projectors which are lubed with EP gearbox oil)

hey presto, problem gone! and the cirtus cleaner makes your car smell of oranges for months