A P0442 alone might well be a loose or leaking gas cap. But, with a P0446, you've more likely got a valve failure elsewhere in the evaporative emissions control system, causing a leak and triggering both codes.

It was smart to get the codes read; but now you'll need to go to a full-service mechanic.

2000 ML 320 overheating. Need help.

I can't find out why my car is still is overhearing and don't know why.
Thermostats removed and still overheating. Radiator new and still overheating. Secondary water pump works fine. No idea why still overheats. Any idea? Thanks.
Ps. It builds pressure on upper radiator hose.

battery is flat. we likely have a dead battery but its why it went dead that matters. if it simply died ? and won't accept a recharge? then its defunct and needs replacing. if battery can be recharged and holds a charge ( when not on car) then we have a power drain on it. possible alternator issue.