I have a 2002 jeep liberty and the check engine light came on. I used my scan tool and pulled code p0442 minor leak in evap. system. what should I check? The vehicle runs and drives fine. I cleared it a day ago and it came on again the next day.

Check small line returning from gas tank to evap cannister for leaks, cracked hose. Also check gas cap for seal.

Check the seal on the gas cap. make sure it is clean. no rust on the filler neck. if there is rust, clean with sand paper and coat with grease. if that is all good it could be purge solenoid.

There are many possible causes for this but 2 popular solutions are a bad / loose gas cap, or overfilling with fuel. there is a multitude of sensors, filters, and connections in the system that can cause the code, but these are a couple basics. many shops are equipped with a smoke machine that hooks up to the system to aid in diagnostics. good luck!