yes seafoam can be used through the pcv system, crankcase, and gas tank. Seafoam would definitly help your car especially if the previous owner was using natural oil.

 

um................. i wouldn't worry about it

all audi have all kinds of inactive faults at any given time for any given reason... its usually audi behavior. don't try to fix what isn't broken. CEL will illuminate if you have a problem worth paying attention to

 

Interesting. I've never heard of SeaFoam used that way. I've always been a big BG fan for cleaning up oil, fuel, or intake systems, but it isn't available over the counter at a parts store. Seafoam works for intakes, but BG still works better. I'll keep SeaFoam in mind as an alternative engine oil cleanup.

 

Seafoam is fantastic for cleaning the oil system - you can really clean a crankcase out with it.