Cadillac Repair: 1990 cadillac deville, cadillac deville, gas tank

Question
i am wondering while im driving my 1990 cadillac deville is losing power. i put on knew cadillac converter knew spark plugs. i am not getting any lights saying anything is wrong. can you please help me thank you. allen

Answer
No CHECK ENGINE light ?.

Let's try a test to see if we can get the car to bog way down and or stall.

Come to a stop and floor the gas pedal and do not let it off the floor until you reach around 60 miles per hour and see what happens.

Do you lose power all the time or just when the gas tank is low on gas ?.