when i have passengers in the backseat of my1998 lincoln contenental my rear end drops and my dash says check ride control
Sounds like your air ride suspension system needs some attention.
Quite likely that some component in the Air Suspension has failed. You may consider changing the suspension over to conventional springs (or whatever is available). I've never worked on the air suspension system of a '95 and up Continental but pre 1995 cost $1000 an axle to replace the air suspension and struts.
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