1994 Cadillac Concours MAP SENSOR REPLACEMENT NUMEROUS TIME

MY 83 YR OLD FATHER HAS REPEATEDLY REPLACED THE MAP SENSOR IN HIS '94 CADILLAC CONCOURS ONLY TO HAVE THE ISSUE COME UP AGAIN AFTER 2-3 MOS. THE ISSUE IS ROUGH IDLING, STALLING WHILE MAKING A TURN OR BRAKING. IT DOES SHOW A CODE WHEN HE CHECKS IT WHICH IS 21. HE RESERCHES THE CODE EVERY TIME TO TRY AND FIGURE OUT WHAT HE IS DOING WRONG. I KNOW FIRSTHAND HE HAS REPLACED IT OVER 4 TIMES. IT HAS BECOME SUCH A BURDEN HE WANTS TO SELL IT BUT DOES NOT WANT A NEW OWNER TO EXPERIENCE THE SAME PAIN HE IS HAVING. HE IS VERY KNOWLEDGABLE ABOUT AUTOMOBILES AND HAS WORKED EXTENSIVELY ON HIS OWN VEHICLES FOR YEARS.

CAN YOU OFFER ANY OTHER INSIGHT OTHER THAN REPLACE THE MAP SENSOR AGAIN?

SIGN ME,
CONCERNED DAUGHTER LJH