Officials said it could take days before prices fall, depending on how quickly refineries can get the winter-blend fuel to market.
"The gasoline market moves on news, and this is clearly good news in terms of supply, because it should be able to increase supply immediately," said Alison apRoberts, a spokeswoman with the California Energy Commission.
Record-setting prices at the pump has also prompted calls for a federal investigation.
Sen. Barbara Boxer, D-Calif., on Monday asked the Department of Justice's oil and gas price fraud working group to look into whether maintenance issues at refineries were being used as an excuse to drive up energy prices.
Boxer's request came a day after Sen. Dianne Feinstein, D-Calif., called on the Federal Trade Commission to investigate, saying residents need to be protected from "malicious trading schemes."
Associated Press writers Christopher Weber in Los Angeles and Juliet Williams in Sacramento, Calif., and business writer Marcy Gordon in Washington, D.C., contributed to this report.
Jason Dearen can be reached at http://www.twitter.com/JHDearen