p0442 code
Thread Starter
Instructor
Joined: Nov 2015
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From: Mboro
CEL code
Got a check engine light with P0442 code..
Evaporative emission system small leakage detected.
Anyone had this issue or know what it could be??
Car has a half tank of gas so I didn't just fill it..
Evaporative emission system small leakage detected.
Anyone had this issue or know what it could be??
Car has a half tank of gas so I didn't just fill it..
Last edited by AirStingray; Jul 4, 2025 at 04:46 PM.
Race Director
Joined: Mar 2007
Posts: 10,930
Likes: 8,102
Got a check engine light with P0442 code..
Evaporative emission system small leakage detected.
Tried clearing the code, and it instantly came back..
Car ran fine on the way home from what I could tell. Anyone had this issue or know what it could be??
Car has a half tank of gas so I didn't just fill it..
Evaporative emission system small leakage detected.
Tried clearing the code, and it instantly came back..
Car ran fine on the way home from what I could tell. Anyone had this issue or know what it could be??
Car has a half tank of gas so I didn't just fill it..
"P0442
This diagnostic tests the Evaporative Emission (EVAP) System for a small leak when the ignition is off and the Conditions for Running the DTC are
met. When the ignition is turned off and the EVAP system is sealed, a change in the fuel tank vapor temperature occurs which results in a
corresponding pressure change in the fuel tank vapor space. This change is monitored by the control module using the fuel tank pressure (FTP)
sensor. With a leak in the system, the amount of pressure change will be less than that of a sealed system."
The diagnostic procedure is long, but I see three possible remedies in it - there could be others.
1. Something about testing or replacing the capless fuel filler pipe or components,
2. Evaporative Emission Canister Replacement
3. Evaporative Emission Canister Solenoid Replacement
Thread Starter
Instructor
Joined: Nov 2015
Posts: 179
Likes: 49
From: Mboro
Never had it. But I looked it up in the Service Manaul. It say this:
"P0442
This diagnostic tests the Evaporative Emission (EVAP) System for a small leak when the ignition is off and the Conditions for Running the DTC are
met. When the ignition is turned off and the EVAP system is sealed, a change in the fuel tank vapor temperature occurs which results in a
corresponding pressure change in the fuel tank vapor space. This change is monitored by the control module using the fuel tank pressure (FTP)
sensor. With a leak in the system, the amount of pressure change will be less than that of a sealed system."
The diagnostic procedure is long, but I see three possible remedies in it - there could be others.
1. Something about testing or replacing the capless fuel filler pipe or components,
2. Evaporative Emission Canister Replacement
3. Evaporative Emission Canister Solenoid Replacement
"P0442
This diagnostic tests the Evaporative Emission (EVAP) System for a small leak when the ignition is off and the Conditions for Running the DTC are
met. When the ignition is turned off and the EVAP system is sealed, a change in the fuel tank vapor temperature occurs which results in a
corresponding pressure change in the fuel tank vapor space. This change is monitored by the control module using the fuel tank pressure (FTP)
sensor. With a leak in the system, the amount of pressure change will be less than that of a sealed system."
The diagnostic procedure is long, but I see three possible remedies in it - there could be others.
1. Something about testing or replacing the capless fuel filler pipe or components,
2. Evaporative Emission Canister Replacement
3. Evaporative Emission Canister Solenoid Replacement
Race Director
Joined: Mar 2007
Posts: 10,930
Likes: 8,102
It did occur to me, and this is speculation, that you could just check that flap at the filler neck - may just check that its closing properly. In the past, emission control related MILs could be just a loose gas cap, but we don't have a gas cap
Edit: I see @jagtoes suggested this too in the other thread. Might work!
