[dburkart]

I started a few weeks ago with code 0442 and we changed the fuel cap. It didnt seem to help and the MIL light has come back on has stayed on even after being reset. I have noticed that it is usually when the gas tank is about half full when the MIL light would come back on after resetting. Anyway, now I have the original code of 0442 and now have 0455. I know what both the codes mean but not sure where to start looking to find the problem. Also, what is the risk if the issue not get resolved? Any help would be appreciated!

Thanks!

[jamesdart]

my truck does that. 03 ram 2500. over 1/2 tank.

[richd]

Here are the causes of P0442:

Common Problems That Trigger the P0442 Code

• Defective or damaged fuel cap
• Distorted or damaged Fuel Tank Filler Neck
• Small tear or puncture in the Evaporative system hose(s) and/or Carbon Canister
• Defective Fuel Tank Sending Unit gasket or seal
• Small split in a seam of the Carbon Canister
• Defective Evaporative Vent Valve and/or Evaporative Purge Valve
• Defective or damaged Fuel Tank
• Defective Fuel Tank Pressure Sensor
• Defective Leak Detection Pump
• Slightly loose and/or worn clamps or hardened O-rings anywhere in the EVAP system

Common Misdiagnoses

• Fuel cap
• Evaporative Purge Valve
• Evaporative Vent Valve

You already did the cap,double check your filler neck, then I would check out for cracks in your EVAP hoses,plus all electrical connections.

[straight6jeff]

Mine had teh same issues.

replace the vac lines.
- at the purge solenoid
- at the charcoal canister by the fuel tank (1/2" line) 2 of em
- at eh hard line junction at the firewall

All total, it cost me 6 buck in line, and an hour of time.

Mine is an 02 and tne lines were dry-cracked severely

No codes for the past 4 months

[brendanc]

Originally Posted by straight6jeff

Mine had teh same issues.

replace the vac lines.
- at the purge solenoid
- at the charcoal canister by the fuel tank (1/2" line) 2 of em
- at eh hard line junction at the firewall

All total, it cost me 6 buck in line, and an hour of time.

Mine is an 02 and tne lines were dry-cracked severely

No codes for the past 4 months

Would you mind listing part #'s or how you found the part #'s?

Thanks.

[straight6jeff]

The Vac lines I replaced did not have part numbers. They are simply cut to length regular fuel rated rubber hose. I went to NAPA to get the lines.

[Drable]

I know at a repair shop I use, they pumped smoke into the system to find where the leaks are. That is about the only way to trace it without guessing and replacing everything, but I do think replacing the hoses like s6jeff did is a good idea.

[brendanc]

huh.

I bought a 3/8" hose and I could not for the life of me get it onto the vapor canister end. How did you get it on there?

[ottoreni]

My Liberty just had these codes come up.

Followed the lines on the underside.

The two rubber hose lines about 6 inches long that turn up into the engine are both severly cracked. By the firewall.
Anyone know the inside diameter of these lines?

They basically create the bend from solid line under the Jeep to solid line up to engine.

Thanks!