2003 Z71 engine light came on today....3000 miles...oil level fine..light is yellow and constant....whats up with this??? bad sensor???wet sensor from car wash?? :uhoh:

take it to the dealer you bought it from, make them fix it, its under warrenty.

The PCM has seen a fault in the emissions system and has set a diagnostic trouble code.
Your vehicle is covered under a 3 year 36000 mile bumper to bumper warranty, so the diagnosis and repair will be no charge to you.

It was a bad ground on coil...