2005 Hyundai Tucson - Computer update?

MECHANIC SAID CAR MIGHT NEED
COMPUTER UPDATE.CAR ALWAYS
STALLING.diagnotic machine no codes show up.

No need to YELL.

A lot more info would be nice

Always stalling, every 3 feet ? 1/4 mile? when stepping on brake? when accelerating? left hand turns? When engine cold? when engine hot?