P0441after head gasket repair (historical?)

Did you double check all the connections you've made to ensure everything is buttoned back up?

It seems like you are getting a code for a gross vacuum leak.

I'd go back over your work.

 

The lower hose on the bottom of the intake manifold comes to mind.

The gasket between the egr cooler inlet and the exhaust manifold is another spot of leaks .

So they're out there and I've dealt with them .

So a bit of experience with the comments I've made with the code you're experiencing.

 

From “Autoworld.com”.
After a few (as they refer to as clean drive cycle) runs, you may be able to clear the code.
History DTCs

These are readings that were out of parameter before, but aren’t out of range now. After a certain number of “clean” trips — trips when a fault doesn’t reoccur — a “current” DTC will become a “history” DTC. These can still be cleared in the usual way, after the data is recorded and you’re sure you won’t need it. The important thing here is not to erase information that could speed up diagnosis.

 

Some bits of this story don't quite seem to jibe. Is "historical" the word Torque uses for a "permanent" code? When you "cleared" it, how did you do that? Permanent codes aren't affected by a scan tool's code clear operation, or by unhooking the battery. They only go away when the corresponding monitor routine in the ECM runs and confirms that the problem no longer exists.

Then, if a permanent code has gone away, it's not going to somehow sneak back as a permanent code; that has to happen by getting reported as a new current code, if the problem is detected again.

P0441 is a code involving the vacuum switching solenoid valve, which you should find on a little bracket low near the left side of the intake manifold (left and right on a car are always when you're facing the same way the car is) with a couple vacuum hoses connected to it, so it would be good to double-check that the electrical and both vacuum connections were reconnected there correctly.

Then you can look in the repair manual (more info) for the "confirmation driving pattern" for that code, which is a way that you can hurry up the ECM's monitor to run and notice that the problem is fixed, which is how the permanent code goes away.

(Edit: though I had never noticed this before, it seems there may be such things as "history" DTCs that are just kept around but can be cleared. That's mentioned in the manual regarding possible codes in the Power Management Control ECU, but I don't see it mentioned for codes in the ECM, which is where your P0441 comes from. I wonder if Torque is using the same word for a couple different sorts of code.)

 

I don't know if Torque is mislabeling a "pending" code as a "historical" code. If it comes back then you should look into things- go back to the scene of the crime as it were. As ChapmanF stated, look at the vacuum switching valve at the intake manifold (aka, the purge solenoid). If the hoses on it are reversed that will definitely cause problems.

The engine ecu opens the purge valve to suck gasoline vapors out of the evaporative emissions canister (from the gas tank) and burn them in the engine. The ecu has a pressure sensor at the canister and tank to help monitor if there are problems or leaks in the evap system.

The P0441 code essentially indicates that the engine ecu sees a vacuum/ pressure reading at the sensor that doesn't agree with the commanded state of the purge valve. Either the valve isn't opening when it should (no vacuum or pressure change when expected), or doesn't close (and seal) when it should (there is vacuum when there shouldn't be any) . See the service manual for more details.

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I'm wondering a little more whether it is lumping "historical" and "permanent" together. There are such things as "historical" codes (in the Power Management Control ECU, not the ECM), and there are such things as "permanent" codes (in the ECM), and they are kind of similar in that they are memories of codes that were current in the past, but they behave a bit differently. (At least that's my reading of the manual.)

"Historical" codes you can "clear". "Permanent" codes only go away after you have fixed the problem and the associated monitor completes and confirms that you did.

 

The manual, FWIW, gives a specific confirmation drive cycle for every trouble code. The one posted somewhere else for a different code will not be of much use for this one. When you look at the confirmation drive for a particular code, you can usually say "oh, yeah, that would create the kinds of conditions this code's monitor would need to judge this code's issue."

There is such a thing as a "universal trip", which is described early in the manual once, and it is one ingredient of many different codes' confirmation patterns.

The nice thing about permanent codes in the ECM is that there is that All Readiness utility that can tell you whether the associated monitor has completed yet or not. It sounds like you've already found that. Permanent codes in the battery smart unit can be more perplexing, in part because there doesn't seem to be a similar utility for those.

(Hmm, I've never checked what the "Engine and ECT" All Readiness utility does, if you ask it about a code that hails from a different ECU. My guess would be "not much", but I haven't tried it.)

 

Do everything people mentioned above. And once you've exhausted all that I'm thinking keep disconnecting 12v and resetting system and a long road trip running more than a tank of gas through vehicle in one sitting and it should clear up.

 

Best of my recollection that'd be really hard to do. Still, not even connected, that's always easy.

There is a confluence of hoses running under the intake air box, I've put everything together at least once with the laps reversed (one that was supposed to go under going over instead), and found the air box wouldn't seat properly, something like that.

 

When they give you a procedure involving Techstream, mainly that's because Techstream is what they would use, naturally.

In steps 1–3, Techstream is being used to clear DTCs. If you have another tool that can clear DTCs, you can use that.

Every "confirmation driving pattern" will start with clearing DTCs ("even if no DTCs are stored"), because that also resets all the monitors to 'incomplete', which means they will run again at the next opportunity, which is what you want.

In step 6, Techstream is being used to enter maintenance mode, but there's also a non-Techstream chicken dance for doing that.

In steps 8–9, Techstream is being used to check what trouble codes are present. You already have something that can do that.

There shouldn't be any need to play "maybe disconnecting 12 volt over and over" sorts of games. First of course you want to make sure any issue with the purge valve really has been fixed. Once you're sure it has been, putting the monitor back to 'incomplete' status and then giving it 15 minutes in maintenance mode to run to completion should detect that the problem was fixed.

 

As mentioned, you don't HAVE to have Techstream, but it sure is handy. With it you can tell the car to perform the evap system test. You can view the data as the test runs- see if and at what step it has a problem. And the evap monitor will be complete afterwards. (great if you have to get emissions inspection done).

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