P1441 and P1444 Engine Code

Got in my truck to go to work and shortly after starting the truck I heard a strange sound and the check engine light went on. OBDII read P1441 and P1444. I've now spent an hour or so researching the problem. I live in CA so it seems that a bypass is not an option, because I need to pass smog every 2 years. I don't know how I could afford to buy all these parts, but how do I even know which ones to buy? Is there a diagnosis process to figure out which parts need replacing in the SAIS?

I really just don't even know where to start and I'm terrified to take off the manifold, but I can't afford to have a mechanic do this job.

Thanks for any ideas/help

 

My bad - I was wrong on something. Hold please.

 

Ok, yep. SAIS. But possibly some good news. Tell me, what maintenance did you do recently?

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So here's the deal, @Squire343 and the possibly good news.

The SAI system has two valves, on the back of the head. They are triggered open/closed when the SAIS pump is running, which is only during cold starts. This open/close function is controlled by the two solenoids (the look for the orange boxes, circled below, for their power harness), those valves are sitting over the passenger valve cover. You will notice both of those solenoids have a short vacuum hose attaching themselves to a shared metal rail (see orange line below). Each one has another vacuum line (yellow line below) that runs from the solenoid to your SAIS valve. The sole purpose of that solenoid is, when the SAI system kicks in, they are commanded to open, which pulls vacuum from the intake (blue line in the image) back to the valves, to open/close them as vacuum is added/removed.

There is a VERY solid chance you fucked up, depending on what you were doing maintenance-wise, and either (A) failed to hookup their vacuum source or knocked it loose, (B) hooked up and/or disconnected the solenoid's vacuum lines incorrectly, (C) detached the vacuum lines that run between the solenoids and the valves at the back of the heads, or (D) something else I'm missing.

Let's think about this logically.

You have codes indicating both valves are not in the position that's expected. I suspect based on the symptoms, BOTH valves slammed shut. We could deduce from that. whatever the issue is, it impacts BOTH valves. Looking at the picture below, think about this. What one failure could cause both the valves not to open/close as expected? The solenoids are using vacuum to trigger the valves. Is there anywhere in the system they both grab vacuum?

If you guessed at the blue line, you're a smart cookie. That hose provides vacuum to the solenoids, and it attaches up under the intake, above the 1st cylinder on the passenger side.

tl;dr - the first thing you need to do is validate your plumbing, to make sure the solenoids have power AND moreso, verify the vacuum hose plumbing. Specifically keep an eye out for that hose in blue, which you can see if you take off the iForce engine cover.

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Side view of all this, trace the lines. Blue line pulls vacuum from intake, feeds the black rail. Black rail feeds the orange vacuum lines to the solenoid, where the vacuum stops. When the solenoids are commanded to open (via those electrical wires), they open that vacuum to the yellow lines, and that vacuum then triggers the valves - makes sense, right?:

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Here's where the hose I'm outlining in blue connects to the intake, i.e. where it gets vacuum to force the rear-of-head valves open/closed, those same two valves the OBD codes are referencing.

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PS - I'm also going to link you back to the SAIS main thread. It shows you the valves and will give you additional info: https://www.tundras.com/threads/secondary-air-system-sais-replacement-info-and-instructions.90175/

Look. Don't think you need to fully understand this stuff, but take a second to read it. The system is pretty simple. I don't know why the fuck people bypass this shit, or see it as daunting. And I also suspect a LOT of people replace the entire system (or bypass it totally) when the issue could be something as simple as a loose vacuum hose, a disconnected solenoid harness, or something equally stupid.

 

Ok everything you said makes sense to me, and I really appreciate your thorough explanation. I checked the lines as best I could. I disconnected the wiring harness' going to the solenoids, and checked to see how they look and they look good. I reconnected them. Checked all the hosing and all connections look good. I checked the blue line you were talking about and what I could see looked good, but the part reaching the bottom is inaccessible to me. Is there any way I can check that connection better without a tiny camera or something?

also the only maintenance Ive done recently was an oil change. I haven't really done anything in the engine bay since I got the truck a few months ago.

 

It could just be a fluke. Try clearing the codes.

Get a 10mm ratchet. Pop off the plastic "iForce" cover there on the engine. You should be able to look around the left-hand side of the throttle body and follow that braided sleeve up to the intake port.

 

I cleared the code and I’m letting the truck cool down completely so that I can see if it stops on its own. That’d be nice.

I removed the cover and I still can’t see where that line ends. Let me attach a photo so you can see what I’m seeing.
I can’t see where the hose attaches to confirm it’s on there snug. Looks like it’s going up though so I’m assuming it’s a good connection.

one questions I have is can I drive my truck? From my understanding the whole SAIS is disconnected from the driving function of the truck and only serves to reduce admissions during a cold startup, so I would assume it’s safe to drive but I don’t wanna do more damage

 

To answer the latter of the questions, yes, if SAIS, you can drive no problem. SAIS only runs for 45-60 seconds from a cold startup *IF* the outside temps are above a certain freezing point.

Your real "don't drive" red flag is a flashing check engine light.

• Solid check engine light = "there's a non-critical problem"
• Flashing check engine light = "some bad shit is happening, pull over"

This is something to watch for if the truck stumbles again. And really, the truck can start stubmling because of stupid shit. Dying battery, for example, or loose battery cable - you shouldn't be able to move the cable forcibly by hand, if you can, it's not tight enough!

Sometimes flashing light can be something as stupid/simple as a misfire, because you've got a bad coil or bad plug. But still, that's not something you should dismiss or drive on for hundreds of miles, you should diagnose and repair sooner than later.

Yes, it looks like that hose is probably plugged in. The bib it connects to points downward on the other side of this ridge I'm pointing at. From the right angle, I can absolutely see the end of the hose on my truck. You may need a mirror.

Also, that hose should be popped into the clamp I circled here, I believe.

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alright I started it up cold after clearing the code and letting it sit. Code didn’t show back up. Still a deep rumble while idling and now I can’t remember if that was there before.

 

If you can take a video with a smartphone, then go to www.imgur.com and upload it, then give us a link to the upload page, others here can weigh in and give opinions.

All you need to do is paste the upload page link into a reply and the forum will auto-link it here.

 

thank you so much for explaining that. I was trying to make a zip file

here’s the link: https://imgur.com/a/r6WYfO4

 

Sounds almost like a large vacuum line is loose, that pumping/thumping noise. I thought the brake booster at first, maybe it's one of the PCV hoses? There's one here, I'm pointing the arrow at it. Make sure it's tight on both ends.

BTW, you need to fix the coolant hose clamp, at the vent control. Look at the hoses across the firewall, the small black box. Hose coming out toward the center is not clamped. That's a disaster waiting to happen.

But yeah, check this foam-wrapped PCV hose, and there's a matching one on the other side.

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And honestly, it could just be the SAI pump. Or the valves. If it stops after 45-60 seconds, and only appears when you start the engine when it's dead cold, then it's likely SAIS, either pump or valves, or a loose hose(s) to one of the two. Next thing I'd do is trace the two (yellow lines above) vacuum hoses around to the back, make sure they're not loose.

 

Checked all the hoses you said and they all seem good. The light hasn’t come back on so I’m thinking it was a fluke? I’ll keep my eyes and ears open.

Was this the hose you were saying wasn’t clamped?

 

Correct, and I clearly see where you've moved it back to the right place, good on ya!

You really DO NOT want to have that hose pop off while driving down the road, or you'd have coolant spraying all over your engine bay. The coolant hose is probably chemically attached to the heater actuator valve bib at this point, but not worth risking having it improperly clamped and flopping off.

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Thanks for letting me know about it!