How Do You Fix The Secondary Air Injection System?

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In our humble opinion there are three option to address faulty Secondary Air Injection System. They are as follows.

Option #1: The most expensive option is taking it to the Dealership and replacing with Factory/OEM Components. On average, most Dealerships will quote between $2,000 – $3,000 for parts and labor. Depending on your engine size, you may need to replace both Air Switching Valves and could involve removal of the intake. However, replacing the Air Switching Valve only partially addresses the Secondary Air Injection System and even worse may only be temporary. This option does not prevent the other Air Pumps or Valves from failing or even guarantee the new Air Switching Valve from failing again in the future.

Option #2: Once you have ruled out taking it to the Stealership you have confidence in your local garage or even doing the job yourself. This in combination with using aftermarket parts will save you a chuck of change. WARNING! DO NOT replace Secondary Air Injection components with cheap aftermarket parts. An initially attractive choice, aftermarket parts will end up costing you more in time and money in the long run. These components are more failure prone then the factory parts. It is not uncommon for them to fail a few weeks or months after installation. This is largely due to the poor-quality materials used to make them and it is not unusual to have aftermarket parts warrantied 2, 3 or even 4 times because codes return.

Option #3: The most comprehensive and cost-effective solution is the Hewitt Tech Bypass Kit. Our Secondary Air Injection System Bypass Kits and Kit Addons are engineered to address multiple types of fault codes across entire Secondary Air System. Additionally, the “Plug and Play” design is compatible with the factory harness which mean you will not have to remove the intake. That said, if you want to get out of Limp Mode, turn off your Check Engine Light, avoid future failures and save thousands of dollars; a Hewitt Tech Secondary Air Injection Bypass kit is what you need.

The following includes details from our Blog "Secondary Air Injection Bypass Kit Comparison". We hope this information will help you better understand the failure prone system and if you have any question do not hesitate to contact us on the forum or through our website.

Hewitt Tech Bypass Kits
Hewitt Tech bypass kits come in two generations: Gen 1 and Gen 2. When deciding which kit is best for you, please note that our solutions are vehicle specific and error code specific. That said, compatibility depends on your vehicle’s year, model, and engine size. Additionally, the error codes that are present will play a factor in bypass kit selection and will help determine if you need any kit add-ons.

It is also important to understand that Gen 1 and Gen 2 bypass kits operate differently and address different subsets of SAIS fault codes. Please also be aware that installation varies according to engine size and bypass kit selected. After reading this article, we encourage you to use the “Search By Vehicle” feature on our website to find compatible bypass kits. Individual product listings will provide further details.

Gen 2 Bypass Kits
The Gen 2 is Hewitt Tech’s most comprehensive bypass kit and the best solution to address or prevent secondary air injection system failures. Unlike the Gen 1 bypass kit that only manipulates the operation of the SAIS, the Gen 2 bypass kits fully emulate it. Why is this an advantage?

First, the Gen 2 can address mechanical and electrical SAIS fault codes, limiting the potential need for kit add-ons. Secondly, the Gen 2 is compatible with Toyota’s most recent ECM flashes and recalibrations, including ECM programming for Flex Fuel models. Lastly, since the Gen 2 emulates the SAIS, monitors will show as ready and complete. The Gen 2 bypass kits will include block off plates to prevent future damage of pressure sensors by exhaust.

Gen 1 Bypass Kits
Our basic bypass kit, the Hewitt Tech Gen 1 prevents operation of the SAIS at cold soak start. It enables you to clear the check engine light, “limp mode” and error codes related to mechanical SAIS faults. The Gen 1 bypass kit is compatible with most Toyota and Lexus vehicles manufactured from 2005 to 2012, as well as select vehicles manufactured in 2013. It’s made with automotive-grade materials and is designed to blend in with the factory wiring harness.

This bypass kit includes a module, a harness, block off plates, and a starter relay wire. The starter relay wire, which is only available from Hewitt Tech, ensures that the module actively prevents the SAIS from running on every start. The Gen 1 bypass kit is NOT compatible with Flex Fuel models or vehicles with certain ECM reflashes.

Please clink on the Link above to continue reading about...

• Which Bypass Kit Is Right For You?
• Gen 2 Bypass Kit Variations
• Gen 1 Bypass Kit Variations

Additional Secondary Air Injection Resources
To learn more about what is the SAIS or SIAS error codes click on the following “Must Read” Hewitt Tech Threads:

- What Does the Secondary Air Injection System Do?
- What Do my Secondary Air Injection Codes Mean?

Disclaimer
It is illegal to remove, dismantle, or otherwise cause to be inoperative any pollution control device required by federal, state, or local emissions law. No other applications are intended or implied.

 

Hola, 2013 taco, p0418 error code. Pump bench tested, harnesses and hoses in good shape . have not tested grounds.
moisture and condensation in hose connecting to valve intakes.
Valves: dirty, but reed valve clear and solenoid valves closed on removal and not stuck with manual manipulation. unable to test electronically for activation and opening/closing. moisture in lower housing of forward valve.

This system has worked for 117k miles & trying to economically diagnose and fix without deleting.

if all mechanical parts are working:
1. is there a way to test the grounding and electrical of the system with voltmeter?
2. I have not read that replacing the AIC control module as any fix. Is this a part of failure? Is there a way to test it? If an error part and replaced does this fix it?
3. Does re-flashing ECU or AIC fix? other forum strings say your bypass will NOT work if ECU is re-flashed. Validity?
4. If ECU re-flashed does your Gen 2 bypass kit still work?

 

@Mizzenmast The P0418 is an Electrical SAIS fault code indicating an issue with Bank #1 Air Pump Circuit. You need to replace the Air Pump with a Factory / OEM component component or I recommend our Gen 2 Bypass Kit which would Bypass Both of your Air Pumps and Air Switching Valves.

Secondary Air Bypass Kit: Gen 2 (Plug & Play) | Hewitt Technologies (hewitt-tech.com)

 

I finally decided to install the HT Gen 2 kit and it has solved the CEL issue.
https://hewitt-tech.com/product/secondary-air-injection-system-bypass-kit-gen-2-plug-play/
thanks all for your input

 

I have a 06 tundra, should I use the gen 1 or 2?

 

@ScottyBro I am happy to walk you through the options compatible with your ’06 Tundra 4.7L. That said, I can briefly provide the basic difference between the Gen 1 and Gen 2 Bypass Kit. The Gen 2 (3 Valve) is a little more comprehensive and will cover both mechanical and electrical SAIS Fault codes. However, please note the installation for these units require soldering wires into the factory harness at the ECM. The Gen 1 (V36H) is the basic Bypass kit that only covers mechanical SAIS fault codes. This is install is plug & plug and much more straight forward then the Gen 2. I have included a link to our blog below that goes more in depth about the Bypass Kits.

Secondary Air Bypass Kit Comparison - Gen 1 vs Gen 2 | Hewitt Tech (hewitt-tech.com)

Gen 2 (3 Valve) $395

- Our Gen II kit emulates the operation of the SAIS and ECM reads as Ready/Completed. It also eliminates all trouble codes dealing with the SAIS with the exception of the pressure sensor. Installs at the Air Injection Driver and Air Switching Valves. (Attention: Does require wires to be spliced into factory harness at the ECM)

+ Covers both mechanical and Electrical SAIS error codes

+ Compatible with Toyota's current ECM Computer flash

+ Compatible with Flex Fuel Modes

+ Clears permanent codes

Installation Instructions


Gen 1 (V36H) $155

- Our V36H kit will prevent the SAIS from operating on a cold start and ECM will read as Not Ready/Incomplete. With this unit, all of the SAIS parts/components will need to remain in place for the computer to see continuity on them. Installs at Mass Air Flow sensor and Engine Coolant Temperature sensor. Also, the starter relay wire will need to be ran from the bypass module to a terminal inside the fuse box.

+ Covers only mechanical SAIS error codes*

*Kit Addons needed for each the following codes

P0418 - Needs Pump Proxy Pack ($155)

P0419 - Needs Pump Proxy Pack ($155)

P0412 - Needs Valve Solenoid Pack ($75)

P0415 - Needs Valve Solenoid Pack ($75)

Installation Instructions


* Important cold weather note, see below in red.

*On some 2005-06 vehicles with 4.7L engines, there is a known freezing temperature glitch in the ECM that can occur when driving in near-freezing or below-freezing temperatures. If you start your vehicle in freezing temperatures, and the P2445 code displays as you near 50 mph, a glitch in the ECM is the cause. However, that is not normally how a P2445 code is thrown, and it also does not typically cause limp mode. If you have a Hewitt-Tech bypass kit installed on your vehicle, there is nothing wrong with the kit, it is a program glitch in the ECM. This glitch has been confirmed to happen on vehicles with or without the Hewitt-Tech module installed, as well as on vehicles with no other SAIS problems and even on vehicles that have had the entire secondary air injection system replaced with new.


Do not hesitate to contact if you have any additional questions,

 

Is this bypass capable by someone that can do spark plugs in a couple of hours?

 

@chetterthecat Yes, especially on the Tacomas 2.7L or 4.0L engine sizes. Everything is accessible through the hood and plug & play. Below I have included the install instruction for the Gen 2 Bypass Kits on the Tacomas. Please do not hesitate to reach out if you have any additional questions.

Gen 2 (Standard) Installation Instructions:

4.0L Tacoma

2.7L Tacoma

 

Hey everyone,

While driving my car started acting super weird and the check engine light came on along with the Trac Off & 4LO (Flashing).

Immediately took it to Toyota to see what they had to say. Overall, they found two errors P2440 & P2442 and advised to replace the Secondary Air Injection system. Below is the overall cost.

Error Code: P2440 & P2442

Cost to fix $3,000
Labor $1,200
Taxes $155
Parts: $1,600

Pump: 176100C030 - Toyota Dealership $800 | Toyota OEM Site: $600
Valve: 2570131014: Toyota Dealership $329 | Toyota OEM Site: $203
Valve: 2570231014: Toyota Dealership $408 | Toyota OEM Site: $262
Gasket: 173770S01: Toyota Dealership $26 | Toyota OEM Site: $4

With little research, I found that, most of the time the valves are the issue and Toyota recommends you to replace the pump once you switch the valves.

Given of how much the pump is I decided to only order the valves & do it myself.

I am not a mechanic & I have never replaced any parts in my car besides lightbulbs & windshield wipers.

I was able to replace the parts in about 3 hours, only because I had to go get some tools that would allow me to do the job.

Here are the tools:

Right Angle Drill Adapter $26
6in hex nut $14
Magnetic Locking Bit Holder $12
10mm & 12mm/13mm (works but not a good fit) (Drive Metric Standard 6 Point Impact Socket) -$30
Innova 5010 code reader $40

Once the valves were replaced, the lights were still on and I used the 5010 code reader to clear the lights and have not had a problem ever since.

Long story short, I spent about $560 (tools & parts). I did not need to purchase the pump ($600 at toyota oem store) and saved about $1,200 in labor from the dealership.

Hope this helps someone else that has similar issues.

 

@Hightechtexan Thanks for taking the time to detail your replacement. Especially, breaking down the cost compared to the Dealership because it is no secrete that have a healthy margin. You also did the right thing by using Factory / OEM Denso components, for anyone going the rout of replacing parts that is the only way to go. That said, I hope you do not run into more SAIS failures in the future. It is not uncommon for owners to have to replace these parts multiple times. The advantage of the Bypass Kit is instead of replacing one or two components (that could fail again) you are bypassing the Pumps and the Valves. If there is anything we can assist with in the future do not hesitate to contact us.