WASHINGTON (AP) — Six Democratic senators representing states along the Pacific Coast asked the Justice Department on Tuesday to investigate the role of oil refineries in gas spikes that occurred in May and October even as crude oil prices were declining. Gas prices jumped last month in California to more than $5 a gallon. Analysts said a web of refinery problems were to blame. But the senators say a review of California refinery emissions data revealed inconsistencies between the time refineries were actually producing petroleum products and when maintenance shutdowns were publicly reported. They said misleading reports of shutdowns could …