p0442 cel come on again

[DRamSrt10]

ok guys, the CEL come again so i found that it is p0442 again but i did change new gas cap so i am guessing it probably is from any pipe or something, i got under of truck and i found a little punch hole on second muffler (the big one round) and it let a little air out and water leaking too so i am guessing it probably is the reasons that cause the CEL come on so what should i do? buy a something to fill up the punch hole from autozone? any help would be great!

 

[mauiSRT/10]

I cant imagine a hole in your muffler would cause a CEL as the sensors are way before the mufflers and most of us have changed them out.

Did you replace your gas cap with a factory one? I have heard aftermarket ones sometimes can trip codes. Is that code the one for the gas cap error?

patrick

 

[DRamSrt10]

the factory one caused the code so i bought new one from autozone with lock key which make it go away then now it is back on so idk whats going i will post a pic, also how can u post pic in here?

 

[mauiSRT/10]

the factory one caused the code so i bought new one from autozone with lock key which make it go away then now it is back on so idk whats going i will post a pic, also how can u post pic in here?

Click post reply or quote then scowl down and you will see "manage attachments", click browse and pick a picture from your computor. Just follow instructions from there. Its really simple.

Any chance your factory gas cap was not on correctly ie crooked? That could cause the CEL. You also might have some sort of emissions sensor that went out too. That would be covered under warranty. Happened on my hemi truck.

patrick

 

[Muzzy]

Make sure that when you fill your truck up, that you do not try to pump extra fuel in after the pump stops. If you try to pump in extra fuel it will flood the evaporative purge system. This is the second most common cause of the MIL P0442 besides the gas cap not being tight enough. If the malfunction does not occur again in 40 warm-up cycles, then the MIL will clear on it's own.

-Muzzy

 

[shade]

WHats a warm up cycle?

 

[Muzzy]

A warm-up cycle is when the engine reaches operating temperature. A DTC (Diagnostic Trouble Code) will stay as pending, which causes the check engine or MIL to stay on until the PCM has been reset manually using a diagnostic tool or the fault has not be detected for 40 successful warm-up cycles. If it was based just on engine starts, all the conditions may not have been met to cause the fault. That is why they set it so the engine has to reach operating temp. If the fault was not detected in 40 successful warm-up cycles, then the DTC will no longer be pending and stored as a historical code. It stores them historically to help techs diagnose intermittent problems.

If you have a factory service manual, this process is described in detail in the emissions section.

"DESCRIPTION - TRIP DEFINITION
The term “Tripâ€￾ has different meanings depending on what the circumstances are. If the MIL (Malfunction Indicator
Lamp) is OFF, a Trip is defined as when the Oxygen Sensor Monitor and the Catalyst Monitor have been completed
in the same drive cycle.
When any Emission DTC is set, the MIL on the dash is turned ON. When the MIL is ON, it takes 3 good trips to turn
the MIL OFF. In this case, it depends on what type of DTC is set to know what a “Tripâ€￾ is.
For the Fuel Monitor or Mis-Fire Monitor (continuous monitor), the vehicle must be operated in the “Similar Condition
Windowâ€￾ for a specified amount of time to be considered a Good Trip.
25 - 4 EMISSIONS CONTROL DR/DH
If a Non-Contiuous OBDII Monitor fails twice in a row and turns ON the MIL, re-running that monitor which previously
failed, on the next start-up and passing the monitor, is considered to be a Good Trip. These will include the
following:
* Oxygen Sensor
* Catalyst Monitor
* Purge Flow Monitor
* Leak Detection Pump Monitor (if equipped)
* EGR Monitor (if equipped)
* Oxygen Sensor Heater Monitor
If any other Emission DTC is set (not an OBDII Monitor), a Good Trip is considered to be when the Oxygen Sensor
Monitor and Catalyst Monitor have been completed; or 2 Minutes of engine run time if the Oxygen Sensor Monitor
or Catalyst Monitor have been stopped from running.
It can take up to 2 Failures in a row to turn on the MIL. After the MIL is ON, it takes 3 Good Trips to turn the MIL
OFF. After the MIL is OFF, the PCM will self-erase the DTC after 40 Warm-up cycles. A Warm-up cycle is counted
when the ECT (Engine Coolant Temperature Sensor) has crossed 160°F and has risen by at least 40°F since the
engine has been started."

-Muzzy