P1441 Code "Evap System Flow During Non Purge"
 

Hi, new to the forums so I apologize if this is a current topic, I couldn't find one on it...anyways, my 1996 RS 3.8L Camaro threw this code awhile back. I didn't notice a difference at all, just a little rougher idle. I used my scanner to erase the code a few times because I couldn't tell a difference.

However, lately it idles terribly. Not horrid but it's noticably rougher. It hasn't thrown the code for..almost 9 months. I replaced the Canister Purge Solenoid, and the grommets that connect from the throttle body to the Purge Solenoid. I also replaced the PCV and it's gasket. None have made any difference so I'm wondering what else I can do to troubleshoot this issue?

Again, no code has been thrown for some time. The idle has consistently gotten worse. Without replacing every moving part of the emissions system, I'm looking for anyone who might have some ideas to help me?
Thanks a lot.

Derek

Check for any vacuum leaks.
Also, your gas cap could be bad. It actually plays a part in the sealed evap system.

I did pass emissions earlier this year, after if threw code, and they did the gas cap test. Would that mean it's okay? The cap also is only 3 years old, I'm not certain what the life expectancy of a gas cap is...?

I've had em as old as the car before, over 18 yrs old without causing issues. It's life expectancy can vary, depending on what conditions it's been subjected to. Did you save your old cap, or have another one? For fun, throw the old one back on and see what happens.

I too have had ones (pre-computer controlled emissions) that were stock from the 70s that still apparently did their job fine.

I have the old one somewhere. I'll try and hunt it down.

Apparently, this is a common code that's out there - I had it too and it went away with replacing the TB-to-evap solenoid line.

Also - depending on what was leaking with your system - you might have some build-up at the throttle body. May be worth taking it off and cleaning it.

Oh, and the bad idle might not necessarily be related to the emissions system, but something like fouled plugs. You could also pull one and check to see how they look, too.

This may be of help (from ALLDATA)

P1441

SYSTEM DESCRIPTION
This DTC tests for undesired intake manifold vacuum flow to the evaporative emission (EVAP) system. The control module seals the EVAP system by commanding the EVAP canister purge valve OFF and the EVAP canister vent valve ON. The control module monitors the fuel tank pressure (FTP) sensor to determine if a vacuum is being drawn on the EVAP system. If vacuum in the EVAP system is more than a predetermined value within a predetermined time, This DTC sets


DTC P1441
The table illustrates the relationship between the ON and OFF states, and the Open or Closed states of the EVAP canister purge and vent valves.

CONDITIONS FOR RUNNING THE DTC
DTCs P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0125, P0440, P0442, P0443, P0446, P0449, P0452, P0453, P1106, P1107, P1112, P1114, P1115, P1120, P1220, or P1221 are not set.
The ignition voltage is between 10-18 volts .
The barometric pressure (BARO) is more than 75 kPa .
The fuel level is between 15-85 percent .
The engine coolant temperature (ECT) is between 4-30°C (39-86°F ).
The intake air temperature (IAT) is between 4-30°C (39-86°F ).
The start-up ECT and the IAT are within 9°C (16°F ).
The vehicle speed sensor (VSS) is less than 121 km/h (75 mph ).
CONDITIONS FOR SETTING THE DTC
The control module detects vacuum during a non-purge condition.

ACTION TAKEN WHEN THE DTC SETS
The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.

CONDITIONS FOR CLEARING THE MIL/DTC
The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not tail.
A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
Clear the MIL and the DTC with a scan tool.

DIAGNOSTIC AIDS
An intermittent condition could be caused by an improperly installed or damaged EVAP canister purge valve or a temporary blockage in the EVAP canister purge valve. To repair a blockage in the EVAP system refer to Evaporative Emission (EVAP) System Cleaning.

TEST DESCRIPTION


See attachmet, sorry its blurry, i'll try to make a better copy

Steps 1-7

Thanks for the replies and help.

I do have a new set of ACDelco plugs and Taylor Thundervolt wires I was to install, and then upon examination it was more work than I could do at the time, so I've been putting it off. The plugs and wires have about 45,000 miles on them, so I'm not ruling out their time is due.

I'm still looking for my gas cap, and I'll get back once I try those two issues. Thanks again fellas.

I had this code and i had the two vacuum lines running from the purge valve switched. Code went away immediately when I found that.

why are you entrained on the evap system if you don't currently have a code? It could be a lot of things causing a rough idle.