2003chevy pu dies at stop lights, low idle whats wrong?

Yea id definately try cleaning ur throttle body 1st. My 03 1500hd had the exact same bad idle after my battery went bad it would die at lights unless i kept foot on gas i cleaned throttle body runs perfect now took 30min cost 8$ for cleaner at autozone and theres how to videos on you tube

I had the same problem with my 2001 silverado 4.8L ext. cab. Chevy had trouble with the I.A.C. (Idle Air Control valve). Carbon-soot build-up rsulted in rough idle and at times stalling. The entire system had issues, MAF (mass airflow sensor), TB (throttle body) carbon build up, intake manifold gasket leaks. Depending on how many miles are on the truck, try replacing the IAC valve. This controls the idle sped at a stop. Also try cleaning the throttle body bore and butterfly plate with throttle body cleaner. Replacing the IAC will result in a rough idle upon start-up. The computer will have to "relearn" the correct idle speed after running for 15-20 minutes while in park. My 2001 drove me crazy with rough idle problems, had the dealer reset the computer twice to the original factory settings. All started around 60,000 miles. Good luck, I've worked on chevys for over 20 years and have built several engines, This rough idle / stalling issue has all owners very angry. One of chevys brillant ideas to control carbon-soot build-up, redesign the PCV valve and remove the check valve inside to improve vacuum flow....HUH? Let me know how things work out.

Make sure your air filter is not clogged and the air box is unobstructed. squirrels love to build nests in the tubes.