2003 Ztec Focus ZX3 with oil in vac line?

Has anyone had an issue with oil getting into the vacuum lines? I took my car to get the fuel injection cleaned and the guy there told me that I had oil in my vacuum lines which was why my fuel injection was so dirty. Sure enough there was a long slick of oil that came out of the tail pipe once he cleaned the fuel injection system.

How does oil get in their? Faulty PCV?
Please advise
Thanks
Mike T.

Worn rings or a bad pcv valve can cause your problem. Replace the pcv valve if you haven't already.