EVAP emission help needed

I am getting a 1441 error code that will not go away.
The code is for "Evaporative emissions (EVAP)system flow during non-purge".
I have replaced the gas cap (2X) and the canister purge solenod valve and the error code will not go away.
The car is now running rough at idle and I get a blast of gas vapor everytime I take the gas cap off.
Any suggestions?

[TARick]

Has anyone successfully removed this blankety blank EVAP stuff from their car?

Or am I looking at a trip to a Chevy dealer?

[my95z28]

I get a loud sucking noise everytime I remove my gas cap as well, but I have no error code.

[MP81]

I get a loud sucking noise everytime I remove my gas cap as well, but I have no error code.

Same here...it's just pressure, which I think/am hoping is normal.

[JoeliusZ28]

mine does it 1/2 the time and i have no code either

[apyah]

I am getting the same code and have replaced everything exept the canister by the back fuel necjk, thats the last part, they say if you get charcoal from there in your lines it will give you that code, mine is a 96 camaro z28. they say that purges right after start up usually a few minutes after starting the car, I always clear it and it wont come back until next time out. so I think I will do the canister next it is 98 dollars at the dealer. Alen

[TARick]

Thanks I will look into the canister. Thanks.

[SS4Matt]

i ripped all that evap shit out of my car when i put in the sumped tank. i must have saved a solid 10 pounds with that nasty charcoal canister out as well

[Transamsfast]

I forget if i still have the code, i did the gas cap 3 years ago and noid last summer.. i have SES on but.. its a car that gets messed with what do you expect

[TSTONE]

here's the flow chart - and im checking som other stuff

DTC P1441 Evaporative Emission (EVAP) System Flow During Non-Purge



Circuit Description

The EVAP vacuum switch is a normally closed switch connected to ground, mounted in the vacuum line between the EVAP canister and the EVAP solenoid. 12 volts is supplied to the switch through a pull-up resistor in the PCM. When the PCM commands the EVAP canister purge solenoid valve open (purge ON) and engine vacuum draws the evaporative emissions from the canister, the EVAP vacuum switch opens (signal voltage high) providing feedback to the PCM that the EVAP system is operating. When the PCM commands purge OFF, the EVAP vacuum switch closes (signal voltage low) confirming purging has ceased.
Conditions for Setting the DTC

• DTCs P0100, P0101, P0102, P0103, P0106, P0323, P0325, P0327, P0332, P0335, P0336, P0372, P0400, P0403, P0410, P0412, P0420, P0430,P0441, P0443, P0500, P0502, P0503, P0506, P0507, P0530, P0531, P0719, P0758, P1415, P1642, P1652 not set.
• ECT less than 115°C (239°F)
• IAT greater than 3°C (37°F)
• Engine speed between 500 and 3000 RPM
• TP Angle less than 50%
• MAP less than 70 kPa
• BARO greater than 77 kPa
• Purge not enabled
• The PCM detects high signal voltage on the EVAP vacuum switch signal circuit when the PCM is not commanding purge ON.
• Fault present for 5 seconds

Action Taken When the DTC Sets

• The PCM will illuminate the Malfunction Indicator Lamp (MIL) on the second consecutive drive trip that the diagnostic runs and fails.
• The PCM will record operating conditions at the time the diagnostic fails. The first time the diagnostic fails, this information will be stored in Failure Records. If the diagnostic reports a failure on the second consecutive drive trip, the operating conditions at the time of failure will be written to Freeze Frame and the Failure record will be updated.

Conditions for Clearing the MIL/DTC

• The PCM will turn the MIL OFF after three consecutive drive trips that the diagnostic runs and does not fail.
• A last test failed (Current DTC) will clear when the diagnostic runs and does not fail.
• A History DTC will clear after forty consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
• PCM battery voltage is interrupted.
• Using a Scan tool.

Diagnostic Aids

Before replacing any components, visually/physically check for the following:

• Mis-routed harness.
• Rubbed through wire insulation.
• Broken wire inside the insulation.
• Kinked or damaged vacuum hoses.
• Physically damaged system components.
• Inspect components and vacuum lines for traces of carbon or other contaminants. The presence of foreign material may be causing a restriction in the system or preventing the solenoid valve from closing properly. Either condition may cause a DTC to set.

For intermittents, refer to Symptoms .
Test Description

Number(s) below refer to step numbers on the diagnostic table.

1. Since the vacuum switch only requires a vacuum of only a few inches of water to operate (a very small unit of vacuum), a properly operating switch will transition even with the canister end of the hose disconnected and un-plugged.

Step
Action
Value(s)
Yes
No
1
Was the Powertrain On-Board Diagnostic (OBD) System Check performed?
--
Go to Step 2
Go to Powertrain On Board Diagnostic (OBD) System Check
2
Important: This DTC will set if the vacuum lines at the EVAP purge solenoid are reversed, Refer to under hood emission label for proper routing.

1. Turn the ignition ON, engine OFF.
2. Using the scan tool, check the EVAP vacuum switch status.

Does the scan tool indicate, EVAP vacuum switch No Purge.
--
Go to Step 3
Go to Step 6
3

1. Start the engine.
2. Using the scan tool, check the EVAP vacuum switch status.

Does the EVAP vacuum switch status change to Purge when the engine is started?
--
Go to Step 19
Go to Step 4
4

1. Start the engine. Increase the Idle speed to 1500 RPM.
2. Using the scan tool, command the EVAP canister purge solenoid valve ON and OFF while observing the EVAP vacuum switch status.

Important: When the EVAP solenoid is commanded ON then OFF, the scan tool display should change from Purge to No Purge almost immediately.
Does the scan tool indicate No Purge within the time period indicated?
5 seconds
Go to Diagnostic Aids
Go to Step 5
5

1. Turn the engine OFF. Disconnect the purge hose from the canister (the vacuum line from the EVAP vacuum switch). Refer to Evaporative Emission Canister Replacement . Start the engine. Increase the Idle speed to 1500 RPM.
2. Using the scan tool, command the EVAP canister purge solenoid valve ON and OFF while observing the EVAP vacuum switch status.

Important: When the EVAP solenoid is commanded ON then OFF, the scan tool display should change from Purge to No Purge almost immediately.
Does the scan tool indicate No Purge within the time period indicated?
5 seconds
Go to Step 11
Go to Step 12
6

1. Disconnect the EVAP vacuum switch harness connector.
2. With a test light (J 34142-B) connected to B+, probe the ground circuit at the EVAP vacuum switch harness connector.

Does the test light illuminate?
--
Go to Step 7
Go to Step 13
7
Connect a fused jumper wire between the EVAP vacuum switch harness connector terminals.
Does the scan tool indicate EVAP vacuum switch No Purge?
--
Go to Step 14
Go to Step 8
8
Using a DVM (J 39200) connected to ground, measure voltage at the signal circuit of the EVAP vacuum switch harness connector.
Does the DVM indicate voltage near the specified value?
B+
Go to Step 18
Go to Step 9
9

1. Turn the ignition OFF. Disconnect the PCM connector C2.
2. Using a DVM J 39200, check for continuity between the EVAP vacuum switch signal circuit and ground.

Does the DVM indicate infinite resistance?
--
Go to Step 10
Go to Step 16
10
Using DVM J 39200, check continuity of the EVAP vacuum switch signal circuit from the vacuum switch harness connector to the PCM connector.
Does the DVM indicate resistance is less than the specified value?
5 ohms
Go to Step 20
Go to Step 17
11
Replace the EVAP canister, refer to Evaporative Emission Canister Replacement . The EVAP system must be inspected and/or cleaned before replacing any component. Refer to Evaporative Emission System Cleaning .
Is the action complete?
--
Go to Step 21
--
12
Repair restricted or kinked hose between canister and EVAP vacuum switch, refer to Evaporative Emission System Cleaning for cleaning procedure.
Is the action complete?
--
Go to Step 21
--
13
Repair the open ground circuit.
Is the action complete?
--
Go to Step 21
--
14
Check connections at the EVAP vacuum switch.
Was a problem found and corrected?
--
Go to Step 21
Go to Step 15
15
Important: Contamination can cause the switch to fail. Refer to Evaporative Emission System Cleaning for inspection/cleaning procedures.
Replace EVAP vacuum switch, refer to Evaporative Emission Purge Vacuum Switch Replacement .
Is the action complete?
--
Go to Step 21
--
16
Repair the shorted signal circuit to ground.
Is the action complete?
--
Go to Step 21
--
17
Repair the open signal circuit.
Is the action complete?
--
Go to Step 21
--
18
Check the connections at the PCM.
Was a problem found and corrected?
--
Go to Step 21
Go to Step 20
19
Important: Contamination can cause the solenoid to fail open. Refer to Evaporative Emission System Cleaning for inspection/cleaning procedures.
Replace the EVAP canister purge solenoid valve, refer to Evaporative Emission Canister Purge Solenoid Valve Replacement .
Is the action complete?
--
Go to Step 21
--
20
Important:: Replacement PCM must be programmed. Refer to Powertrain Control Module Replacement/Programming .
Replace the PCM.
Is the action complete?
--
Go to Step 21
--
21

1. Using the scan tool, select DTC, Clear Info. Start the engine and idle at normal operating temperature. Select DTC, Specific, then enter the DTC number which was set.
2. Operate the vehicle within the conditions for setting this DTC as specified in the supporting text, if applicable.

Does the scan tool indicate that this test ran and passed?
--
Go to Step 22
Go to Step 2
22
Using the scan tool, select Capture Info, Review Info.
Are any DTCs displayed that have not been diagnosed?
--
Go to the applicable DTC table
System OK

© 2008 General Motors Corporation. All rights reserved.

[TARick]

WOW! Thanks
I guess I know what I will be doing Saturday.
I'll let you know what happens.

[TSTONE]

ok - finally had a chance to talk to a tech bout this

you need to check power & ground to the purge solenoid valve & vent valve - also make sure the vacuum is hooked up - next question is did this start following the tank having been down or out - if yes possibly the lines running up to the tank are not connected properly or kinked

if thats all ok - then you can try to follow the flow chart but are going to run into a problem cause you will not have the equipment nessesary to pressure up the system and check for leaks