Secondary Air Injection System (SAIS) CEL P2440 Air Switching Valve

Same thing with my pump. There was no filter. Turns out the filter broke apart and traveled to the valve and got stuck there. My valve was stuck because filter pieces were in the way.

 

Call me an idiot, but where does that thin hose go ? Is it just a breather or does it connect somewhere ?

 

Thanks to all who contributed, especially posts 1 and 17. It's time to give back, I hope this helps someone.
I have a 2007 2TR-FE 4 cylinder with low 60k miles, and about 10 days ago I got the P2440 code (secondary air valve stuck open).
After researching these and other posts, I suspected it had ingested deteriorated filter foam from the secondary air pump.
I removed the cover of the secondary air pump and found no sign of any air filter foam.
I disassembled the pump and cleaned it, still no sign of any air filter foam, and no water in the dust cover under the motor.
I wondered if I could clear any deteriorated air filter foam that might have been sucked into the valve and stopped it from closing fully.
So after I reassembled the pump, I disconnected the hose at the valve, and started the engine.
The air pump ran fine, and I could feel the strong air flow.
I could also hear and feel by putting my hand near the inlet that the valve was open and puffing for a short while, then the pump stopped and I could hear and feel that the valve had closed.
I reconnected the hose and cleared the codes, including a new one P2441 (I think that's what it was - due to the hose being disconnected).
Since then I have had 10 days and 24 cycles, and no codes.
Maybe letting the system operate with the hose disconnected allowed the valve to cough out air filter foam debris?
I'll post again if I get any codes again.

The air pump now had no filtration, so I removed the plastic cap on the intake and replaced it with a Meriton 1 inch filter that I found on Amazon for $8.50.

$9 Auto Car Universal Rubber End Clamp on 25mm 1" Intake Air Filter Black

https://www.amazon.com/dp/B0BS48LGPR?ref=ppx_yo2ov_dt_b_product_details
It seems good quality and similar to the Uni-Filter UP-107 which was quite a bit more at $21.24.
I found out that Toyota have added a plastic cover to the air pump on the 2016-2021 years.
This is presumably to help stop water getting in, which has apparently been a problem, according to other posts.
It's the same air pump as the one in the 2nd generation, so the cover fits perfectly, clips on positively, and covers the Meriton filter nicely.
The Toyota part number for the cover is 17613-0P010, and I found one on eBay for $34 with free shipping.

When I first got the code, I figured I was going to have to replace the secondary air valve, so ordered a new valve 25710-75015 and studs 90126-08031 and gasket for the connection to the pipe to the exhaust 25717-75010.
When my order arrived, there was only one stud in the package, while posts 1 and 17 indicated that you get two.
I emailed the Toyota dealer about it, referencing this thread, and got the following reply:
"Online posts aren't always correct. Toyota sells everything individually. No sets of bolts or clips or nuts. All individual which is why you only received one."
I'm going to have to pick up another at my local dealer, so I'll see what he says.
But if you are buying online like I did, I suggest you confirm with the seller that you need two studs.

 

Two months later and about 3 starts a day on average, and no codes!
In the meanwhile I did pick up a second stud 90126-08031 at my local Toyota dealer, and he also said you get just one stud.
So you would need to specify two of 90126-08031.

 

The Parts I needed for 2.7L engine
AIR SWITCHING VALVE 25710-75015 (All previous versions have been replaced with this)
Stud Hex Lobular 90126-08031 (Old short mount studs replacement, 2 needed)
Toyota Pipe Gasket 25717-75010 (Discard the old gaskets, need to be replaced. Not reusable.)
Pipe not needed if not rusted, but need to be cleaned. (I used Oven cleaner and hot water with a pipe brush, let it try on rag)
Check pump for carbon build up.

Tools needed:
10 mm Socket
12 mm Socket
E-torx Socket E8
Pliers for hose

 

How did you remove the top of valve without removing the whole unit?

For me the P2441 & P2445 P0418 codes went off, I thought it was just the pump. I took apart the SAI pump and found that pump had sucked in the foam filter and the fan had broken. Cleaned the inside of the hose but didn't find any foam pieces. Replaced the pump but 3 days later, the P2440 went off. I'm hoping I caught it early enough that I only need to take the top of the valve apart to remove any foam pieces in there before I commit to removing the whole unit and/or ordering a new valve. Any tips/advice is appreciated.

Also, does anyone know the part number for the hex nut that goes around the stud (P/N 90126-08031). I have a 2.7L 2008 Tacoma.