89' Jeep Cherokee aircare/stalling problem

hi there, i got a problem passing aircare due to the NOx readings being double the passing limit. (all the other readings pass way below the allowable limit) another thing about my jeep is that it will stall sometimes even after it's warm when i pull up to a stop sign or street light. it'll start idling rough when i slow down (brake) and then just shut off. i have to keep one foot on the gas while braking and comming to a stop to keep it running. i'm wonerding if this problem is related to the aircare failure and what you think i should fix.

thanks for your time,
brandon

High NOx is usually caused by a bad or sticking EGR valve. I would start to diagnose there.

thank you very much, i'll check that out.