Code P2446, Secondary Air Injection System Stuck on Bank 2?

2008 TOYOTA SEQUOIA
147,000 MILES • 5.7L • V8 • 2WD • AUTOMATIC
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BENLEE1199
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Hello, my Sequoia (essentially a 5.7L Tundra) just had the trouble code P2446 pop up last night. The engine is still running just fine, so it does not seem to be in limp mode and no noticeable driving issues.

This seems to be a common part to go out on a Tundra, but I am not one to just replace automatically, so is there anything besides a bad valve that could cause the trouble code, and anything else that I can check first?

Also, I assume/hope that even if the valve set needs to be replaced, then I can possibly avoid replacing the air pumps as well, but I wanted to get your input on that as well.

Thank you!
Jul 9, 2025 at 9:25 AM
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STRAILER
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Okay, so my sources say this code is for bank 1, I know most of the internet says it is bank 2 but that seems to be incorrect. This is from Toyota, I checked:

P2446 - Bank 1, Air Switching Valve, Stuck Closed - This means the valve is not allowing air into the exhaust manifold on Bank 1 during the cold start phase.

Toyota Technical Service Bulletin (TSB) EG045-07 and 0157-10: Explicitly list P2446 as Bank 1. Focus on air switching valves, not the pump being stuck on.

So, I would change out the switch valves first. Also, you can check to see if the pump motor works by putting power and ground to it. The blue wire is power, and the black wire is ground. Here are the switch valve locations so you can swap them out and then clear the codes after the work is completed.

It looks like the valve is all inclusive for both bank 1 and 2. You will need to remove the cowl and other parts as well to get to it. FYI.


Bank 1 is on the passenger's side of the engine.

Check out the images (below). Please let us know what happens.







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Jul 10, 2025 at 10:34 AM
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BENLEE1199
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Okay, I will check the pumps to make sure they are able to operate, and I'll plan to replace the valves. Do you know if anyone ever has any success simply cleaning out the valves, rather than replacing them? I know that cleaning parts is not a viable option for professional mechanics, but I'm wondering if I could get the valves working again if I just cleaned out all the carbon buildup inside.

Also, on a separate note, I need to replace all the injectors right now as well, so I might as well do that at the same time as accessing these valves. Are there any 3rd party after market fuel injectors that you recommend for Toyota that are reliable, or should I just stick with the OEM Denso injectors? I'm trying to save as much on injector cost as possible, but I don't want junk either.

Thanks!
Jul 11, 2025 at 8:23 AM
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STRAILER
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It is possible to clean the valves and get them working as long as nothing is broken inside. I would go with the DENSO fuel injectors so you don't have to replace them again :/ Let me know what you find and have a good weekend.
Jul 11, 2025 at 11:37 AM
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BENLEE1199
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As far as the Denso fuel injectors, what would be a reliable retailer for genuine OEM injectors that are the most affordable? There are many fakes online, so when I search for the injectors, it mostly seems to be cheap aftermarket injectors, or ones that say they are Denso, but are clearly way too cheap to be real.
Jul 14, 2025 at 5:54 AM
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STRAILER
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Good eye, I would use RockAuto they have good parts that are real.
Jul 14, 2025 at 7:51 AM