If it's used in the context similar to "Bye" : 잘 가 (jal ga), literally, go (home) well.

we don't usually use that expression. the answers' meaning is similar to what you asked but it's not exact. like other expressions.. for example we don't use 'good morning, good afternoon and good evening' actually we don't have those expressions. usually we say 'have you eaten?.' when we meet people. and i think when you ask somethings about korean. you have to notice honorific words. i think normally your answers are not honorific words. it's very strict rule. when you speak Korean. :)

jar ji-nea = 잘 지내! or mom jo sim hea = 몸 조심해~^