P0442 Buick - how do I know what to get fixed

Question

EVAP system problems checking engine light is on wont pass emissions test

Answer 1

Hi there,

This code is for a small evap leak, it's best to have a shop do a smoke test to find the location of the leak, then repair it yourself to save money. You basically have a leak in the evap system that is .5mm or smaller so it's not really the type of code or problem you can see with your eyes.

One thing you can do is check your gas cap and the fill tube. If the rubber on the gas cap is damaged or the fuel fill tube has rust or rust pits in it, it can cause this type of code.