Secondary Air Injection System "fix"

Update: Take note that the location of your pump is different from one model to another. If it's in a location that is prone to high amounts of water or grime collection then assess the likelihood of any potential damage.

So this fix is to correct the horrible and cheap design of the foam 'filter' used in the system. This filter from my reading online and assumptions is the biggest culprit of damage and issues with other components like the valve switch it shoots air to. What my fix does is eliminate the internal filter with an external K&N filter. The only thing these filters are meant to do is to block debris from entering. Not filter fumes or toxins. This is purely preventative measures and not intended to fix any damage that has already occurred.

I have been driving around and as of yet no codes or issues. Best part is piece of mind and absolutely no noise on start up or shut down other than my intake, motor and exhuast. Long ago I changed over to an electrical fan and highly recommend it.

First step is acquire the new filter. I used a K&N Crankcase vent filter.

Next is remove the one bolt holding the top cap on. There is no need to remove the entire assembly. From there you will see the filter and be able to happily throw it into a fire or the trash. Picture of filter below



Now I had a piece of hose laying around that I decided to use to make the fitting a little more snug and directional, mostly for testing purposes so if this caused any issues I could convert back to oem seemlessly (Final outcome will yield identical results with or without hose connector). I would not relocate the filter too far away nor tap into your intake system. Don't want to make it compete against the sucking power of your motor.

Here comes the tedious part. You'll need a razor blade and slowly slice a larger hole in the rubber part of the filter. I made mine a hair thinner than the outside diameter of the hose so that it'd have natural pressure sealing it. I followed up with a little glue to reinforce the seal but it honestly probably didn't need it.

Last step is to put the top back on and screw in the bolt. Finished result with new filter will look something like this.

 

This seems more like a solution looking for a problem. Those little filters don't actually filter all that well and you're probably allowing more things to get sucked into the SAI pump than if you left the original filter in place.

 

The stock filter has considerably larger holes or pores in it than the K&N filter so I find it hard to believe that the new filter would allow bigger contaminants into the system. Once again the only reason there is a filter at all is to prevent big objects from entering, not to filter dust or fumes. It's been proven that these foam filters break apart and get sucked into the weak plastic fan that spins forcing air to your valve. Once that foam enters the fan the fan will either get stuck or shear sending now plastic and foam to your valve and engine. Once this happens it is likely you will not have any warranty coverage and will have to pay out of pocket to fix. You can not easily eliminate this system due to multiple sensors and a program in your ecu that does a check on it after every 2 start ups or 7 hours being shut down. It's either fix the weak point or buy an aftermarket ECU to not go into limp mode from a code being thrown.

For me I'd rather fix the known issue/weak point and not risk a $250-$2000 fix down the road. Thanks for your thoughts though

 

that is one of the bullshittiest hobo-looking gawd awful things ever spawned from the
depths of 'toyota engineers don't know nuttin, I can do a much better job with WalMart parts...those toyota crooks'

#foampile

 

been planning something like this for awhile now for the same reasons. I dont want that foam to degrade and eff up the air injection pump. Ima take a measuring tape to the inlet and find a breather that requires no cutting or mod to fit.

 

seeing as WATER getting in the system is what is causing them to fail on certain V8 tundras,
I am not sure what is being headed off here on a tacoma pump, especially making the intake more vulnerable to
ingesting splashed water...

 

My truck does not have one. Why not?

 

This is the only reason i can come up with that i dont have one. But my friend has 4x4 and he as well has one. Sooo i am loss as to why mine does not.

 

it has one unless you removed it or someone removed it

they are required to pass emissions and have been installed
on vehicles for many years

if you don't have one and do not have MIL codes, then
somehow the MIL is being bypassed

 

I don't think they started putting them in the tacoma til 2012

 

For real though... OP, take that crap off and put the foam back in.


Only some are failing from the foam. Like home said, water/moisture is the main culprit for pump failure. Secondary to that, carbon build up is the next causing the valves to stick.

 

Negative my friend.Has not been there since purchase, thought the same thing so i paid toyota $70 to smog it and it passed.

 

My 05 had one.

 

Nobody has been able to answer this.

What is MIL codes

 

V6 Tacoma's 2012 and newer have them

4 cylinders may be different, since OP's is an '09 and has a pump.

 

I think I read somewhere that all 2nd gen 4 cyl have one?

The larger engines have them in different locations right? I seriously don't understand how or why water is "splashing" into that pump OR around their engine bay on start up but sounds like they are having fun at least.

I did think about the water issue but decided it wasn't a real issue since this system only runs on startup. Since I don't mud bog or put my engine bay under water and there isn't any water splashing into my engine bay when I'm not driving it (Garage kept or car port), then the risk is pretty moot.

 

malfunction indicator lamp, the actual technical term for that light


often incorrectly called check engine light

 

MIL code anyone?

Yhea no codes. Had yota check that too. Nothing. Not that i believe them.
Is there a way to bypass this i wounder.
And should i go to a scrap yard, find and install one?

 

all 2nd gen I4 tacos have them.

2012+ v6's have them as well.

 

If your truck runs like a champ without one and you don't need it for your local smog/emissions I'd say no and feel lucky.

I personally do not want this system on my truck at all, but simply bypassing or removing it isn't exactly "easy" and certainly not within the normal home mechanics capabilities. I'll explain why to the best of my knowledge and capabilities.

First you need to understand why this system is there and how it works. It's for the tree huggers and emissions primarily. When you first crank your motor it's usually cold and the air temp in plenty of places around the world hit ~40f or lower. The black box sucks in fresh air from your engine bay using a plastic fan and sends that air to your valve switch bolted on your exhaust manifold. From there it enters your exhaust manifold and shoots directly out your headers, then it hits your catalytic converters. By doing this it helps your converters clean the fumes to less harmful ones. I forget which gasses exactly it's for but it's only needed for the first 15-30 seconds on start-up then will shut off. The valve next to your manifold opens and closes and is what keeps you from having pressure issues (Gases coming up to the air injector) The whole system is intended to work one way.

Now that's the mechanical aspect. Next is the sensors and ECU. There are multiple sensors (I am reluctant to say how many but I think a minimal of 2 no matter what you have) and a maintenance check your ECU will perform often. Lastly there apparently "updates" for both the tacoma and tundra that are available or already flashed onto your ecu and I do not believe there is an easy way to know what version flashes you have.

So to bypass you would need to buy resistors or simulators (I'm not aware of anyone making one for us currently so it's up to you to fabricate one) to tell your ecu that the air temp is 40+ and everything is alright so it doesn't activate the system on start up. This requires your current system to be fully operational at time of install. Your ECU also does a check to ensure proper operation every two start ups or after 7 hours of being turned off. So ultimately you still need to leave things everything in place just the system wont actually run. It's a lot of work for not much in return. A company called Hewitt something has been making bypass kits for tacomas and tundras but offer only limited years and models with still strict requirements for successful install. They also wont sell any for years between 2008-2011 due to it throwing additional codes that throw our trucks in limp mode.

To do a successful remove would simply require an aftermarket ECU and block off plate. This allows you to remove it all and be fine... But isn't exactly "cheap" nor "easy". If my system ever actually fails I may/probably will just go that route.. Because why not just supercharge it and go all out at once.

Like I said I am no expert on this system, it's merely what I have read and understand so far.