Does anyone has an idea what does check engine codes PO442 and PO300 mean?

EVAP leak and random misfire

For the EVAP leak code take a look at the rubber tubes that come up to the EVAP port next to the battery tray or in the rear of the Jeep near the EVAP canister. When you get under the KJ you cant miss it, near the rear vacuum hoses in and out of it. Most of the time one or more hoses have become dry rot and leak causing the EVAP system to swear six ways from Sunday.