Secondary Air System / SAIS Replacement Info and Instructions

If your truck is truly in limp mode, there should be a code unless the light is somehow burnt out. Limp mode is more like someone is retarding things though, not what you describe, it's running in degraded/less response mode "fail safe" if you will.

Remove the negative battery cable on the truck for 10 minutes. i.e. force the ECU to forget things. Go for 20 minutes just in case. Put the negative battery cable back on. Start the truck.

If your issue persists, you may want to hit up the 2nd Gen forum over here, since this is 1st Gen and we may not have as much info. It's almost like maybe the Gen2 trucks have issues with ABS/WS sensor and not being able to detect speed may be screwing with things, but I know nothing about '07+

 

I have been getting a code P0412 secondary air injection system switching valve "A" on my 2006 4.7 Tundra. It has 270K miles and I am the original owner and never replaced any components in the SAIS.
I live in Montana and don't have to do smog tests. I have been reading threads on SAIS and information from Hewitt and Rutech about their bypass kits and they do not address the P0412 code.
I erase the code and it comes back on after 20 miles or so. Truck runs great.
I have had recent problems with packrat infestation. It got in the air filter box and made a nest and clogged it up, I had a MAF code and cleared it, cleaned out box and replaced filter. Ran fine a few days before this came up. I don't know if the problem is related. I don't see any chewed wires yet.
Does anyone have any suggestions or know of a solution without removing the plastic intake manifold...or any solution at all?

 

I called Hewitt and told them the details. They told me to pull the intake to check the wires. Sure enough a rodent had chewed up the wires.
Now that I got the intake off, should I replace the starter? Or is an aftermarket starter not worth buying? Are there good factory rebuilt ones still available?

 

Not necessarily starter replacment, but I'd do the contacts. My OEM starter is still fine at 332k miles.

 

If you must replace, aftermarket isn't worth buying. Get a new Denso starter. Don't buy from scAmazon, fleaBay, wallyworld etc. Go to Summit Racing or Rock Auto, they have authenticated/verified product lines, virtually no knockoff risks.

 

Thanks for the info, Shifty. I checked Rockauto and Summit and they don't have the right Denso 28100-50101 (2KW) starter so I might have to get a rebuilt OEM from a dealer.
I'm thinking I won't replace any SAIS parts while I'm in there, it worked fine before the rodent attacked the wire and since smog test is not required here, I could probably fix any future problems with a Hewitt kit. Should I replace the SAIS air hose or anything else while the manifold is off? I don't want to do this again.
I plan to replace the O ring for the coolant tube.

 

I personally wouldn't repair anything that's not broken. I also wouldn't bypass, but that's just me. Other may have a different opinion. I've seen enough cases where bypassing opened a can of worms to know it's not a good fit for me.

That said, @NickB_01TRD posted this info, we have an ATL dealer running a sale for 25% off OEM parts, and probably free ship: https://www.tundras.com/goto/post?id=3679339#post-3679339

 

Thanks for the tip. I will have to remove the SAIS to replace the starter, are there any parts which self destruct upon disassembly that I should order?

 

I'm confused, why do you need to remove the SAI pump to remove the starter?

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And yes, though, I see it shows doing it in the FSM (step 6), but I'm not seeing why it's necessary based on the pic. I would consult the YouTube University to see someone else do the work in a couple videos to deem why/what you'd need to remove.

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I'm the one that's confused. Maybe I don't need to remove that stuff. I imagine those hoses would crumble if I touched them and they want about $50 for the pair.
thanks!

 

I just looked at mine again, it's not like the one in your pic, which might be the warm weather starter. My starter is less than 1/4" away from that valve. ugh...

 

This is ridiculous. I ordered intake gaskets for my 2006 4.7 from Toyota Parts Express and finally got them 10 days later and what did they send? One bank. How can you replace one side intake gasket? They apparently sell them separately. You can't fix stupid. Now I have to wait another 10 days and pay shipping again.
Rant over.

 

Yeah, I don't think I'd shop with a place called Toyota Parts Express. Not very express, clearly.

 

I promise it won't happen again sir!
I understand that OEM intake gaskets matter on aluminum intakes but not the plastic ones, right? Rather than wait another week I might just buy after market for the other side.
The dealer here, Lithia Toyota never has anything in stock and charges double for almost all parts.

 

I found the gnawed wires and soldered them. I bought a factory rebuilt 2KW starter and put the intake back on. As you see in the pic, the 2KW cold weather starter is longer. To make the valley less hospitable to Norway Rats, I made some land mines out of 1/4" hardware cloth, cut into strips and twisted. Now they can chew wires that are easier to get to.
Getting the SAIS check valves out was easier than I thought, the flange bolts were not siezed in the aluminum. I also replaced the O ring on the water tube while I was in there.

 

Honda/Acura makes rodent repellent tape you can wrap wires and hoses in also to deter them.

I'm going to need to get under my manifold to check wiring, and potentially replace my bank1 knock sensor soon (P0328).

I know my wiring is free of chewing and under-manifold free of rats, I scoped it with a snake cam, but I don't know if there was something in there prior that the PO didn't catch. May be why the 2nd owner of my truck bailed after 10k miles.