Cadillac: check engine light, egr system, service engine soon light

Question
i have a 1991 sedan deville 4.9 liter.
I am getting a service engine soon light and
error codes E48 and E.

car has 100000 miles on it -engine runs rough
when fuel tank shows 4 gallons left in tann or
below 4 gallons.

thanks!

Answer
E48 is an EGR system fault.

however your running problem is most likely caused by the fuel pump rubber hose that attaches the pump to the pickup tube in the gas tank as this hose has a tendency to get weak and or has a split in it and when the fuel level gets low this hose is exposed out of the gas and starts to suck air.

tom