My check engine light

My check engine light came on. I just got my car back from the shop yesturday after three weeks of being worked on. So you understand my problem with taking it back there. I took the truck to auto zone and they said it read i had a vaccuum leak in the engine, or a 02cesor was needed. Can someone please tell me more about these two issues and how to go about trying to fix them? Thanks so much, Donna

Do you remember what the codes were?

Yeah, we need exact codes.

My check engine light came on. I just got my car back from the shop yesturday after three weeks of being worked on. So you understand my problem with taking it back there. I took the truck to auto zone and they said it read i had a vaccuum leak in the engine, or a 02cesor was needed. Can someone please tell me more about these two issues and how to go about trying to fix them? Thanks so much, Donna

We can't do anything with your description, we need the EXACT codes.