when I was down in Catavina for the NORRA they were just about to complete a BP or Pemex across the street from the hotel there. It also has a market that was up and running!
Google show the facility under construction including the market which is now open. I just sent Hotel Mision Catavina an email asking them to confirm the gas station is open and if it has both gas & diesel. If they reply I'll let you all know.