My 2001 Jeep TJ has recently logged 2 codes, P0442 and P0455,can anyone tell me what these codes are and how to fix them.Thanks

 

P0442 - Evaporative Emission Control System Leak Detected (small leak)

P0455 - Evaporative Emission Control System Leak Detected (no purge flow or large leak)

Often times it's a gas cap issue (P0442) so check that first.
Other possibilities are:
* A non-conforming gas cap (i.e. not factory/original brand)
* A small leak/hole in a fuel vapor hose/tube
* Other small leak in EVAP system
* Faulty vent o-ring seal

If the gas cap seems OK, then inspect the EVAP system for cuts or damage to tubes and hoses.