Can some please explain what an ERS leak is and what repair costs? on 2000 Pontiac Grand Am

The service engine soon light came on in my Grand Am. I look it to Advance Auto to have it checked. The guy said it was an ERS leak. I can't find any info on this anywhere. I would like to know what to expect when I take it to the garage for repair. What they need to do, price range, and how long it will be down. He didn't give me the diagnostic code. Thanks.

1 answer
Gonna have to give us a code number on that one, have it checked again and post the code #.