[rpest]

Hi!

I have 2010 XC70 D5 (with 151kw) and for a month, once in a while, there is an intensive smell of sulphur/rotten eggs in the cabin. Battery seems good, no indication that it has failed. Engine works good - no loss of power or anything.
Local independent shop had a look, didn't see anything out of ordinary, used a odour bomb and cleaned the vents, but after a day, the smell came back. I asked them if it could be the catalytic converter that has failed, but they said that if any of the fumes from the catalytic converter were to enter the interior, there should be a hole in the cars bottom but there is none. Smell isn't permanent, it comes and goes, about once in a day, depending on how often I drive.

Vida doesn't show anything, no codes related to emissions or anything.
Has anybody had any experience with this kind of problem? What to look out for, how to troubleshoot?