Hi,

I have an '05 automatic S40 in California and the with an illuminated check engine light.

The mechanic they diagnosed it as an intake problem, replaced the mass air filter and then the 'oil intake' but the light reappeared almost immediately. They then spent another day with the car and now say it needs a new breather box, and mentioned a number of components that are required when replacing that.

I was reimbursed for the mass air filter and intake but is a breather box essential, and would it be possible to replace it myself?

Very grateful for any suggestions or advice.