The p0442 code means there's a small evap system leak, and like you found, the gas cap is often the culprit
I have this code p0442 on my wifes 2019 chev traverse 3.5 liter
I had it in the shop for a new torque converter and it came back with this evaporator emission system, small leak detected code.
In this guide, we'll break down exactly what the p0442 code means, why it happens, how to diagnose it (with a little help from the vd80bt lite obd2 scanner), and how to fix it—even if you're a.
Evaporative emission control system leak detected (small leak) description
There is a hole of more than 1.0 mm (0.04 in) dia
In evaporation system or fuel.