PO442 code on my 2004 mit galant,LS V6 3.8 how to fix an evap problem small leak

code p 0300 refers to random/ multiple misfires detected ===causes --spark plug/s--HT lead/s--injector/s --ignition coil/s--low compression --wiring
most likely low fuel pressure and injector problems
code p 0442 refers to evaporative emission (EVAP) system ---small leak detected ===causes hose connection/s--intake leak-- EVAP canister ---EVAP canister purge valve
it also refers to --large leak detected ===causes ---petrol cap loose ,/missing---mechanical fault ---EVAP pressure sensor
code p 0455 refers to EVAP ---large leak detected --all those stated plus EVAP canister purge valve
code p1680 refers to electric throttle control (ETC) monitor ---processor fault ===causes --wiring--ECT monitor

code - po442=evap leak medium detected

code-po456=evap leak small detected
look at fuel cap or leaks in rubber hoses

code p0442 refers to evaporative emission (EVAP) system--small leak detected====causes hose connection/s---intake leak--EVAP canister---EVAP canister purge valve
it also refers to evaporative emission system --large leak detected (fuel cap loose/ off)===causes---mechanical fault--hose connection/s--EVAP pressure sensor.

p1299 cylinder head protection activated running hot- po442 small leak detected in the evap system or gas cap loose

2005 Galant with code po442 this code is for an evap leak, a small leak, check the gas cap for any cracks in the oring and then you will need to check the evap lines, these line sometimes crack and allow vacuum to leak, this system is computer controlled to allow venting or purging.
most of the time a small evap leak may be due to a bad gas cap but other times it could be a line or rusted filler neck or other problems. the best way to find such a leak would be with an evap smoke machine, thee machine pumps smoke into fuel tank and lines for evap system and with vent valve shut the system should be air tight, then you look for smoke and where smoke is that is your leak, most repair shops have the machine, note : some leaks are so small the smoke can not be seen ,at this point soap water in a spray bottle is helpful, spray lines and other areas to see bubbles.

codes po441 po442 po455 po456. code po441 - EVAP system no flow during purge conditions.code po442 -EVAP system small leak detected conditions. code po455 - EVAP system large leak detected conditions.code po456 - EVAP system very small leak detected. possible causes loose damaged missing fuel cap.fuel tank sensor disconnected or failed. ORING on top fuel sending unit leaking.purge valve vapor line clogged disconnected or purge solenoid failed.vent solenoid not closing or has failed.

Hello and welcome. these codes are for a evap system leak, could be a gas cap, vent valve, purge valve, tank seal leaking, or any one of the fuel fuel vapor leaking. the only way to know for sure what part needs replaced is to have the system smoke tested with a evap test station.

EVAP Codes. You will have to go thru entire evap system,looking for a small leak (po442) Hoses,Switches,Valves etc. See if you can borrow a smoke machine.

po442 is evap emission control system leak (small) 1 of the lines for emissions is leaking. po455 is-- emission control system leak (large). turn off light with code scanner after it is fixed.

P0442 EVAP System Small Leak (0.040") Detected


EVAP fuel tank or canister vapor hoses leaking or damaged
EVAP system component leaking, damaged or has failed
Fuel tank cap is loose, or the cap release pressure is incorrect
Leak detection pump damaged or leaking

You can try the gas cap first, if that does not help you will need to take it to a repair shop, Small leaks are very hard to find. If you want to know what turns on the light here it is.

Cold engine startup (ECT sensor from 40-90�F and within 10�F of the BTS input at startup), fuel level more than 1/2 full, engine running, EVAP leak test "on", and the PCM detected a leak greater than 0.040� but less than 0.080" somewhere in the system.
This code sets in 2 Trip(s).