P0412 code

Truck just starting throwing a P0412 code. I’ve tried to clear it and the second I do, it comes back. What and where to check first?

 

This kit or similar.

 

Just watched this. What a PITA it is taking off the intake plenum. I'm new to Toyotas but, doing the same on my 3.0L Honda is 1/3 the job. So it's Ok to run without the secondary air injection system?

 

The CEL will come back no matter how you clear it, because it's malfunctioned. Taking the plenum off is not a PITA, but replacing the smog valves on the back near the firewall is a real problem. Lol.

 

Will fixing the P0412 require replacing the smog valves?

 

It's not necessarily. The P0412 seems like a famous failed air injection pump. Since you take out the air intake plenum, it's a chance to replace or at least double-checking, then cleaning up all related components at once. If 1 of them fail, it's a PITA to redo everything. On my truck, I even replaced the starter even it's still good. The factory smog valves are hard to fail, because they're just generated by the vacuum that opens the valve inside. I bought 2 new Japan smog valves, but ending up using 1 new and 1 old. 1 new one failed. I think both old ones are still good. I removed the old ones, soaked them in Sea Foam overnight, then scrubbed off the carbon. After cleaning, I hooked them to a vacuum line in a car to check for function. They all worked fine.
For the air pump, I use the Dorman 306-010 Electric Pump on Amazon for $123. I found out it's made for various American cars, but the core is exactly the same for Tundra and other Toyota models. I think Dorman is American company. I kept the factory pump shell, and replaced with the Dorman motor inside. It's working well for over 4 months now. Don't use unknown cheap China air pumps. I used 2 previous ones, and they only lasted for 2-4 weeks.

 

I have 2006 dbc, used the bypass kit several years ago, it's a easy install and work's great.

 

Bingo

 

Sounds like we need a discussion on which system is the best. Which is it? The Hewitt system is quite a bit more expensive than the Rutech kit but, it does come with the ignition wire. I'm not sure one wire is worth it, though. What do people think?

Here's what I've seen out there so far. Are there any others I should be looking at?

Hewitt
https://hewitt-tech.com/store/index.php?l=product_detail&p=12

Rutech
https://rutechsolutions.com/products/aip47?variant=38455630340

Random Ebay kit
https://www.ebay.com/itm/Toyota-4-7...-NO-CUTTING-/162582156626?hash=item25daa6d552

 

Anyone out there?

 

Heller???

I’d chime in, but think this is a later 1st Gen Problem? The earlier models without vvti do not suffer this?

 

Same, I would probably go with Hewitt but I would be interested to hear from someone who actually has one of the kits on their truck.

 

I used the Hewitt kit, it's been several years with no problems. Give them a call and tell them what codes you have and they will tell you what kit you need.

 

If you can't tell, I'm having a hard time with this one. I'm trying to find a justifiable reason the Hewitt unit is $80 (44%) more than the Ru unit. I'm not sure I ever turn the ignition on for more than a couple of seconds without starting the engine.

 

I never had the CEL code pop up on my 2006 DC but I did have the vacuum sound associated with the SAIP upon starting the engine. I read that this would eventually lead to a CEL and possible limp mode so I installed the Hewitt bypass kit. Whether it's worth the extra money I can't say. I did like having the starter relay wire that is not available with the Rutech bypass kit. I figured if I was going to do this one time I'd rather spend a little more and get the one with the extra feature. It's been working great and I haven't had any issues. I didn't even install the block-off plates since I never ran into a CEL code. Hope this helps.

 

Here's some advice that was good to follow. Just called them and for a P0412 you have to buy the SAIS bypass kit as well as their Valve Solenoid Pack. I wouldn't have been real happy if I would have bought the SAIS kit and it didn't completely fix my problem. Ordering the goods now.

 

Your wallet. On the counter.

 

No kidding. These kinds of fixes aren't fun. Truck doesn't sound better, doesn't look better, isn't more capable and doesn't go any faster. I'm paying to make a system the truck didn't even need to have in the first place, inoperable. What a downer.

 

Whoa!

 

I can speak from experience I bought the rutech kit and had Mass air flow sensor codes throwing all the time. I took the kit off and they never came back. Rutech explained that if your computer was updated at the dealer which mine was then their kit doesn't jive well with the ECU and will throw xodes so I sent it back. Talked to Paul Hewitt and he knows his product well. I cannot say for sure but I think rutech is a cheap attempt at a copy of hewitts without knowing anything about the product or putting any engineering into it. From what a gather he puts alot of time and money into research and development of his kits and he walked me through my rutech kit which wasn't even his and he didn't have to do that. For that I believe it's worth the extra cost. His customer service and knowledge is excellent!

 

I am thinking about buying the huwitt bypass kit. Code p0412 is up. If I install this kit can I still pass yearly Texas inspection?
I’m worried about the computer diagnostic test mostly.

 

Give them a call. They're remarkable knowledgeable and helpful. I'm confident they'll be able to answer any question you have sufficiently.

 

I will do that. Thanks!

 

I installed the Hewitt-tech bypass kit on my 2006 Tundra. I live in Texas in a county where they check for emmissions (smog) and attach an OBD-II scanner. Mine recently passed less than 6 months ago. Hope this helps.

 

That helps a lot! Thank you simonmiles

 

I started getting three codes (P0333, P0412 and P2433) I researched the problem and found this thread. I agonized over ordering the Hewitt bypass kit. I searched all over the engine for wire damage. None visible from the top so I called Hewitt. With the codes my truck was throwing I would have had to buy anywhere from $490 to $1000 to fix my issue. The first thing she asked after I gave her the codes was if I had any wires damaged. I did not order the parts and began a deep dive into my engine. Using an inspection scope I was able to snake it under the intake manifold. Found chewed wires (see photo). So I ordered replacement gaskets for the intake manifold and when they came in I started the process of pulling the intake manifold off. Once removed I was able to see several wires chewed apart. I repaired all 6 wires and cleaned the rats nest out. I buttoned it back up and now it runs like a champ again! I highly recommend checking for rodent damage first all over the engine compartment. And the video above was a lifesaver.