Hewitt-Tech Secondary Air Injection Bypass kit (2012+ 4.0) (UPDATED 21-OCT-2016)

*** UPDATES AT BOTTOM OF OP ***

Searched on here, only found a couple of threads with not much info but thought I would put this review out there anyway for an inevitable failure of the 2nd air injection pump.

Truck threw a code: P2440 TOYOTA Secondary Air Injection System Switching Valve Stuck Open Bank 1. Truck was in limp mode and couldn't for the life of me figure out the issue. Basically after a long search and some trial and error I came across . After reading every single reply to it, and contacting the manufacturer of the kit, we both came to the conclusion this was the solution for me.

If you have a Toyota warranty and your pump has failed, I highly suggest you get the issue fixed instead of going this route which basically nullifies the pump's existence. Apparently the new pumps are more reliable than the old ones, and they fix the issue. Also this happens more often to the 2nd gen Tundras with the 4.7L motor but is also possible for failure to all 1GR motors with a secondary air injection pump (which in our Tacos I believe are only 2012-2015 model years). I was right at 70k when this occurred and was out of warranty, and the repair bill from Toyota was sky high (IIRC around $2500 parts and labor) but this was $145 shipped to my door and after 10k miles of using this product, the truck runs like new again. I highly recommend it.

Install time took me about an hour and I was taking my time. You have to do some splicing in to the OEM harness for the MAF sensor wiring, if you don't feel comfortable doing this I would contact someone who is. There is also a single 18 gauge wire (might be 16 gauge) that you need to run to the starter solenoid relay in order to get the bypass module to work with your truck. Again if you don't feel comfortable doing this - I would contact someone who does.

There are also plates you need to install to block off the piping from the pump to the headers, this was the most difficult part by far. I broke a bolt head off and the stud remained in the hole, I had to drill it out and retap the hole. Having a second set of hands really helps for this part but I did it by myself and it wasn't too bad.

Here is the link to purchase the module, there is also the vendor's contact information with a phone number on there, with a PDF of instructions for installation. He is a really nice guy and will answer your questions the best he can. If you need pictures of anything I suggest looking over the tundra solutions thread and the instruction pages for installation. If you still need pictures I can upload a few upon request.

First edit - June 30, 2016:
After a few months of using the module my truck started throwing a P011B code which is a malfunctioning thermostat. This is a known issue with the module that I am using but @hewitt-tech claims their new V50 series of modules fix the thermostat correlation code. Thanks.

Second Edit, 21-OCT-2016:
I uninstalled my HT bypass kit. The bypass kit I received was throwing a code for a bad thermostat, and I couldn't live with the light. After a few emails to HT about the issue - he stopped responding. But ultimately his last response was buy a new kit that doesn't throw the code. I asked about getting a partial refund (as this kit probably cost $10 or so to make) and was given the good old shaft. I asked about getting one for a discount since I bought the earlier one, I was given the shaft once again.

After an uphill battle I stopped caring, I pulled out my suck valves, bit the bullet and spent $300 on new valves and installed them. No lights, no limp mode, I can hear the vacuum again when I turn the truck on. Now it's a time bomb that I don't know when it will go off and throw the codes again when this shit system fails inevitably again.

 

Nice wright up, had my code throw out a p2445. Contacted Hewitt-Tech about it, he stated his kit will take care of that code . Purchased the plug and play, even though you still have to solider one wire onto the blade of the starter relay. It's a little confusing which blade on my 05 4 cylinder truck. Found out it's the widest side silver blade facing the windshield. I was having problems with twisting the wire around it to make a good connection, so I file a spot nearest to the body and solider the wire to the blade. Now another code came up! Code po418 meaning a bad AIR INJECTION PUMP, when I now ask Hewitt about this. He stated you need a working pump or for $80 MORE! I can sell you a resistor, and you need to send me your pumps connector. I went ahead and purchased a used working one, everything is good now. So for plug/play, block off plates $225, wire ties, black plastic wire conduit , a used working pump $100, and about 6 hours of my time. I've got $335 invested in it! That's pretty good for jerry rigging it! Their's a company that started to rebuild the pumps, now that these trucks are going out of warranty. Got this, from a company with a CrossRef number for my truck, I have the 05 2.7l engine. http://www.carid.com/cardone/remanufactured-secondary-air-injection-pump-mpn-33-2504m.html

 

Very good information. I don't think my pump failed, I just had the valve stuck open code, but $100 for a used working pump sounds good since once you install it, it won't run again so it can't fail .. haha.

 

Supply and demand my friend! You're system has to be working to have this jerry rig by-pass system to work. Suggest to try to clean the valve some to see if it works. Went online Partshotlines.com to look at used air pumps today, their's half the number and the price now starts at $330 plus shipping! Most of them now say call us for price quote! This stuff is getting very old and it's starting to break down. At least someone sees an opportunity to start rebuilding them. https://www.tacomaworld.com/out/?ur...econdary-air-injection-pump-mpn-33-2504m.html http://toyotaparts.bochtoyotasouth....-engine/emission-system-cat/a-i-r-system-scat

 

Another possible issue is when the air injection pump goes bad. The system kicks in demanding for the pump to work and it doesn't. The exhaust now back feeds into the hose and bad pump. It'll get so hot that'll melt and cause an engine fire. That's why allot of people are by-passing this system! If the Toyota warranty is up, you should buy the Hewitt-Tech by-pass kit before it fails. Other half brain option is to get an air pump check valve and put it in line so their's no way for the hot exhaust to back feed into the pump. That way you won't be scrambling to find replacement parts. You do have auto insurance in case of a engine fire right?

 

hmmm.. so if I want to get rid of the pump to make room for a dual battery setup, I can delete the pump using this kit?

 

hmmm...


hmmm...

 

Mine doesnt have one.

 

Thats because you are a 2011

 

Hey guys,
My name is Paul from Hewitt Technologies Inc. I just happened across this thread, saw some confusion and just wanted to chime in and give you guys a little more info to go by. Thank you for the initial post Large.

Common codes you can get when the system fails or starts to fail are the stuck valve codes codes P14## (P1441,P1442 etc...), the P2440/P2441 or P2445/P2444 with or without the P0418.
We have a list of codes you can check yours against here: SAIS Trouble Codes and you can also look at the installation instructions ahead of time here: SAISBM Installation Instructions
With any of these codes the kit would be able to prevent the system from operating, let you clear your valve codes and prevent the system from going into limp mode.
The block off plates will isolate the system from the exhaust (permanently closing the exhaust valves) so you don't have to worry about the exhaust leaking back into the system and cause any problems.

99% of the time a P0418 code indicates that the motor of the Secondary Air Injection Pump is either electrically shorted or an open circuit. This code like any of the other "circuit" type codes requires that you repair the fault or replace the component to clear. This is because even though the system is prevented from operating the computer is still looking for the pump motor, exhaust valves, pressure sensor and pump driver to be connected and within spec. This is also the reason you can't just disconnect or remove the components with the current bypass kits.

In the case of the P0418 code we now have a SAIS Pump Replacement Pack that will let you clear the P0418 without touching the actual air pump. The SAIS PRP installs at your Air Injection Driver which is located on the inner fender well of the engine compartment. You could replace the pump but we have seen problems with the cheap generic pumps and even some of the re manufactured pumps not being within spec and causing the same problem. Our pump replacement packs are priced roughly the same as a reman. pump and will never go out of spec are easier to install and much less expensive than a factory pump.

Plug and play units are now available for all the 4.0L engines!(edit 5/17/16)

If you have any questions please fee free to email us support@hewitt-tech.com or give us a call Toll Free 844-307-7671.
You can also contact us directly through our our website as to view the installation instructions. http://www.hewitt-tech.com

 

@armyofsquirrels

 

One repair:

 

Nice find! Burnt comm wire acting as a fuse could confirm why the pump fails first and i have only heard of 2-3 blown pump fuses. Other failures have been shorted windings from overheating and corrosion/degradation of the brushes and comm. The over current damage is usually because the pump vanes are deteriorated and causing drag and the motor draws more than its rated current.

 

For anyone not wanting to splice into their factory harness, you can order the URD MAF extension harness, and splice into that. Basically making your own plug and play unit.

 

So does this delete the air pump?
Edit: I am removing my inner fenders and would like to ditch the pump completely, would this allow that?

 

I was blown away when my taco threw the code I was only at 14K miles. It spent two weeks at the deal. The tech said it was uncommon for the Tacoma to do it. He said that the tundras had more issues with it.

 

That would work! Our efforts to find those two connectors has never yielded anything. I have ordered one of those extensions to see if I can get a part number off of them so we can offer a plug and play kit for the 4.0L. If not it would at least give me something i can get my suppliers to compare to.

The current bypass kits will not let you remove the system components like the air pump, valves or driver without getting other codes.
If you wanted to remove the pump only you could however use the bypass kit and put one of our pump replacement packs on which would take up less room in the location of the pump driver.

 

The Tacoma was one of the last toyota vehicles to get the Secondary Air Injection System added to it. It has not been a problem in the past because they just haven't been on the road as long as the Tundra and other vehicles that got the systems in 05. We have seen more 08 and newer vehicles that have thrown the codes with extremely low miles than any earlier years, even less than 10k miles.

 

The air injection pump on my 2015 was faulty a 7,800 miles. It made a screeching sound one morning during startup and the codes showed up. Toyota replaced it under warranty. I'm not worried about it failing again since I have an 8 year extended warranty. Before the warranty is up, I'll definitely bypass.

Toyota part # 176000P040 List price is $795.83 and $574.14 from Camelback.

 

The kits are now available for all model years of the 4.0L as a plug and play kit with the kits for the 08 and newer being available only as plug and play!
I have also heard from a few customers that there is some confusion about the pumps needing to work to use the bypass kit.
There are a few different answers depending on "how" your pump is not working.

There is a pump that is not working because the pump vanes are deteriorating or chewing themselves up against the pump housing or foreign debris in there.
In this instance you would typically hear a vacuum cleaner type noise on your cold start and the kit will work just fine to prevent the system from running(stopping the pump), let you clear those codes and keep you out of limp mode. Occasionally the pump can fail in this manner because the pump vanes are just gone and it doesn't make any noise but the same applies.

Then there is a pump motor that has been damaged. This is the typical end result of letting a pump motor to continue to run. The motor will usually open circuit a winding or the brush wire as seen in a post above.
At this point if the fuse did not blow( not very common) you will get a P0418 code. In this instance the kit will still work as above to prevent the system from running, let you clear your other codes and keep you out of limp mode but you will continue to have the P0418 code setting the CEL. Typically it will not cause limp mode by itself but on some of the newer vehicles it can.
Hope is not lost though. If you have the P0418 code you can put one of the bypass kits and one of our pump replacement packs on there and get on down the road. No more pump to fail and the factory pump can be removed or left in place.