Hewitt Technologies - SAIS Bypass (1 Viewer)

[erkelbot]

The 4x4 versions do give you a bit less room than the others but still doable. I just did them on my 05GX and didn't think it was that bad compared to my 05 Tundra DC but then again I have down quite a few now for myself.

Doable, agreed. Definitely take your time though...aside from finding the right angle for the approach, you'll want to hit those flange bolts hard with PB Blaster and let it sit. They can get VERY brittle. If they break, as the instructions say, "drilling them out is extremely difficult".

 

[BltByKrmn]

There's no reason to do the block off plates if you don't have stuck valves. Here's my experience and information I've gathered:

For those of you who own or are considering a 2005+ GX470 or later year 4th gen 4Runner with the revised V8, I would strongly suggest buying a $45 secondary air injection pump bypass from Jeff Cole jeffcole75@gmail.com While his bypass is a simple product, his instructions are great and he includes zip ties, velcro and wire connectors to make it pretty damn close to plug n play.

A few months ago I started to hear a shop vac type sound coming from the engine compartment on cold starts. I knew it was a pump, but I figured it was tied to the suspension air pump and I missed pulling a fuse when I switched to coilovers. I only drive the truck about 4 miles every day during the week so I never paid it much attention. Last week the mild shop vac sound turned into a high pitched dentist drill sound so I decided it was time to look into it. Since it's pretty warm in NY now, it would only last for 30 seconds and the pump would turn off. After some further research, it was definitely my secondary air injection pump that was going bad, and since I had the high pitched noise it was going bad quickly. While pump failure is a problem, the bigger problem is the valves within the air injection system getting stuck open. Luckily up to this point I just had a failing pump, so CEL or limp mode yet.

So I order the bypass and roll the dice driving the car 4 miles each day, hoping the valves don't get stuck.

What happens the morning the bypass is to be delivered? CEL code P2440, Secondary Air Injection System Switching Valve Stuck Open Bank 1, and limp mode. So now a potential worst case scenario has happened, with the valve stuck in the open position I can't just install the bypass. Limp the truck to the train station on back roads, leave it to deal with after work.

Jeff was able to give me the following directions to get the valve to close:

1 - Turn the truck on, let it warm up to full operating temp
2 - clear the CEL (with OBD box or disconnect the battery for 10 minutes)
3 - turn the truck off
4 - turn the truck back on and since the coolant is still at operating temp, the SAIP will not try to kick on and it will try to close the valve
5 - drive the truck to check the valve is closed, if it's closed the CEL will not come back and you will not go into limp mode
6 - if the valve is closed and CEL doesn't return, park the truck and do NOT turn it back on until you install the bypass
7 - if the valve is open and the CEL returns, go through the above steps again

From what I understand, as long as you don't go for a long time with a failing SAIP system, you should be able to get the valves to close with the above. It only took me 1 try to get the valve to close, so it worked perfectly for me. That said, if you have a situation where the valves just wont close, you may need block off plates or to take the valve block apart and do it manually (huge pita).

Apparently Toyota knows this system is a problem and if you want to replace it because of emission problems (I'm looking at you California), it's a $4k job at the dealer since you have to remove the intake manifold.

 

[ADVFamilyHauler]

I will be installing the plates for peace of mind. Doesn’t seem too hard

 

[CarolinaGX]

I installed the plates because that is what was recommended in the instructions. I soaked studs/nuts in PB Blaster overnight and then I was able to loosen the nuts but did not remove them. There was enough room to slide the plates in and then tighten everything back up.

 

[hewitttech]

There is a reason all of our hewitt-tech kits come with the block off plates. The plates are an important part of the solution even if you don't have valves that are currently stuck open or leaking. They permanently close the valves so you don't have problems with them causing valve stuck open and limp mode later on. Just because the system is no longer operating the valves can and do leak later on down the road all the time. We still get customers that call back later because they go back into limp mode months/years later and the first questions is "Did you install the block off plates?", no?, then you need to do that first. Please stop saying the plates are not needed, they are important. You are always better installing the block off plates even if you don't want to, it is the only way to not have problems with the valves leaking in the future.

 

[ArBrnSnpr]

Thanks for chiming in.
Always nice to debunk the internet lore.

 

[FJ40CaptBob68]

So my question concerns CA emissions testing. I just had the valves replaced $700 and now the cracked exhaust manifolds left and right $$2500 all so it will pass smog and turn off all the warning lights.
Does this bypass kit Still allow my CA vehicle to pass smog? For future reference and my mechanic's continuing education.

 

[dzsipo]

So my question concerns CA emissions testing. I just had the valves replaced $700 and now the cracked exhaust manifolds left and right $$2500 all so it will pass smog and turn off all the warning lights.
Does this bypass kit Still allow my CA vehicle to pass smog? For future reference and my mechanic's continuing education.

I have run some diagnostic tests on the vehicle after SAIS Bypass Kit installation and there is no sign of emissions system failures. The only thing that could cause you to fail a smog inspection is if the inspector notices the extra wires and asks about it (which they probably don't ask because they probably don't want to know) or if you bring it up. Emissions system tampering is probably not legal for on road use in any state. Contact Volkswagen for more information on this. The short answer is that it should pass a CA emissions test. You might want to avoid having the dealer perform the inspection.

 

[hewitttech]

Must have missed the notifications on this last week. We sell our kits for off-road use only. The federal emissions law states it is illegal to bypass or otherwise make inoperable and emissions system for on highway use. As such we sell our kits for off-road use only. Now as far as emissions goes either of our older kits or newer kits will let an off-road emissions exempt vehicle pass an emissions test. Our Older GenI kits kits are a little more obvious and the emissions monitor for the secondary air injection system will never run or show as complete. With the GenII kits they are much less obvious and don't have any starter relay wire connections or connections to the intake or intake and engine coolant harnesses. To take it a step further the GenII will make the ecm and emissions monitor think the system is still on the vehicle and operating correctly. The GenII will show the emissions monitor for the secondary air system as complete and be less likely to cause a fuss during inspection when ALL of the emissions monitors have completed.

 

[HomersCanyonero]

@hewitttech is there a GenII kit for the GX470? Don’t see GX470 in the drop down menu for GenII

 

[hewitttech]

@hewitttech is there a GenII kit for the GX470? Don’t see GX470 in the drop down menu for GenII

All GX470 fall under the GenII-3V version of the GenII kit.. All of the 4.7L Lexyota vehicles with the exception of the 07-09 Tundra 4.7L and 08-09 Sequoia 4.7L are covered by the 3V versionof the GenII. These are the vehicles that have the air pump and three air switching valves underneath the intake manifold. We separate these into their own listing because they require extra connections and three solder connections at the ECM. This is because unlike the other GenII kits there is no way to make these 100% plug and play without removing the intake manifold. The ECM is easy to access but the three solder connections are critical. You can find them here GenII-3V: GenII Secondary Air Injection System Bypass Kit - https://hewitt-tech.com/store/index.php?l=product_detail&p=94

 

[HomersCanyonero]

Got it. I was only looking at the featured products in your homepage and saw GenII kit there. I didn’t know that was the wrong one for gx470 and I didn’t realize there were more products in another section of the web site.

 

[Rednexus]

While replacing the starter in my GX470, I preemptively address the SAIS issue by I installing the $50 Slyfox75 kit from eBay. The SAIS tubing to the manifolds was a nightmare to remove to pull the starter, so I elected to not reinstall them and use blocking plates instead. The plates were easy to make for both the upstream and downstream ends of the tube by sawing the tubing off the flange and using the flange as a template to cut the plates out of 1/8 inch aluminum with a dremel. I sealed the plates with muffler cement and bolted the flanges back on. Zero leaks or CELs. The actual SAIS bypass took 15 minutes and works perfectly too. Not bad for $50 and some scrap aluminum.

 

[Alleycats]

Hey guys, is there a coupon code for the hewitt bypass kit?

 

[hewitttech]

Hey guys, is there a coupon code for the hewitt bypass kit?

Hello all my ih8muders. All of our kits have been on sale pricing since the start of Covid and we manufacture everything in house in SC. If you can imagine, that has not been something easy to do for a company of under 10 employees.
However, just for you and for the rest of the month of Jan. 2021 I am going to offer members an additional 10% off any of our kits. You can use the coupon code "ih8mud10" in your shopping cart.

 

[captainva]

All GX470 fall under the GenII-3V version of the GenII kit.. All of the 4.7L Lexyota vehicles with the exception of the 07-09 Tundra 4.7L and 08-09 Sequoia 4.7L are covered by the 3V versionof the GenII. These are the vehicles that have the air pump and three air switching valves underneath the intake manifold. We separate these into their own listing because they require extra connections and three solder connections at the ECM. This is because unlike the other GenII kits there is no way to make these 100% plug and play without removing the intake manifold. The ECM is easy to access but the three solder connections are critical. You can find them here GenII-3V: GenII Secondary Air Injection System Bypass Kit - https://hewitt-tech.com/store/index.php?l=product_detail&p=94

What is the difference between the gen 1 and gen 2 kits? When I look at the listings both of them say that they will work with my 2008 GX470. I obviously don't want to pay an extra $170 unless there is a good reason to do so.

 

[hewitttech]

What is the difference between the gen 1 and gen 2 kits? When I look at the listings both of them say that they will work with my 2008 GX470. I obviously don't want to pay an extra $170 unless there is a good reason to do so.

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The Gen-I units only prevent the system from running. They can only address mechanical codes like the valves stuck open/closed and pump stuck off codes by themselves. For the electrical fault codes or those caused be damaged pressure sensors they need extra kit add-ons. The Gen-I V36H kits for the 05'-07' vehicles connect to the MAF/IAT and the the Gen-I V54H kits for the 08'-12' vehicles have additional connections to the ECT sensor. The Gen-I units all use a starter relay sense wire to trigger the module whenever you start the engine to make sure the unit prevents the system from running. As an example of codes that Gen-I kits need kit addons for; codes like P0418 and P0419 for bad air pump motors or damaged air injection control drivers would require a kit addon called a Pump Proxy Pack (PPP $155) and every once in a while a new air injection control driver. Because the Gen-I kits only prevent the system from running it is still possible to get electrical fault codes in the system later on and need kit add-ons at that point, the most common is the P0418/0419 codes because water settles in the pump motor and corrodes them out of spec.

The Gen-II units are completely stand alone and emulate the entire system by replacing the factory air injection control driver(s) and connect to the pressure sensor(s). There is no connection to the MAF/IAT, ECT and no starter relay sense wire to clutter the engine bay. On a GX/LX/LC 470 this is done with the GenII-3V which also connects to the two VSV harnesses on the top passenger side of the intake manifold and has a three wire whip that goes directly to the ECM to tap into the pressure sensor (there no way to make it plug and play without pulling the intake manifold).
The Gen-II kits can take care of ALL of the codes mechanical and electrical except those caused by damaged pressure sensor(s). They can take care of the electrical fault codes P0418/0419, P0412/0415 and there is no way to get them later on either. The Gen-II kit also prevents having to replace the factory air injection control drivers with new units or replace the air pump fuses if they are blown. The only kit add-ons we have for the Gen-II kits are pressure sensor replacement add-ons which none of our kits can take care of.

The Gen-II is simply the most comprehensive solution for current trouble codes and the prevention of future codes. It is completely stand alone, looks like a factory part, does not have to manipulate the engine temps, does not have a triggering requirement and will even let the secondary air system's emission monitor show ready/complete.

Both kits include block off plates which are still important parts of the solutions, Free USPS Priority Mail shipping, Limited Lifetime Warranty and full Technical support.
Below is a basic comparison of the two kits that cover most instances of the system failures. There are exceptions where certain codes are caused by damage pressure sensors, wiring or even in an extreme case a damaged ECM. Because there are so many specifics to the system we prefer to talk to our customers to discuss the vehicle and the most effective solutions for them.

 

[captainva]

WOW! Excellent response and thank you for taking the time to answer my question so thoroughly! So I understand fully, the Gen II kit emulates the system and prevents all future codes except the case of a failing pressure sensor which must be replaced. It will allow the SAIS system to show ready on OBD. The downside of the GEN II is that it requires removing the intake to install and requires soldering 3 wires to the ECM under the dash (as well as the increase in price). GEN I doesn't require removing the intake or soldering but can result in future issues and will not allow the emissions to show as ready within OBD? That said and given that the SAIS in my truck is still working with no errors what would you recommend?

 

[hewitttech]

WOW! Excellent response and thank you for taking the time to answer my question so thoroughly! So I understand fully, the Gen II kit emulates the system and prevents all future codes except the case of a failing pressure sensor which must be replaced. It will allow the SAIS system to show ready on OBD. The downside of the GEN II is that it requires removing the intake to install and requires soldering 3 wires to the ECM under the dash (as well as the increase in price). GEN I doesn't require removing the intake or soldering but can result in future issues and will not allow the emissions to show as ready within OBD? That said and given that the SAIS in my truck is still working with no errors what would you recommend?

None of our kits require removing the intake manifold for any reason. Unlike the GenII kits for the other engines the the pressure sensor we need to connect to on the majority of the 4.7L vehicles is underneath the intake manifold. This is the reason for the 3 wire connections at the ECM so you don't have to remove the intake manifold to connect to the pressure sensor. The ECM is really the only place to identify and be able to make the connections to the correct wires. I think you have the rest of it. For simple prevention it is hard to beat the V36 if you have a 05'-07'. For the 08 and newer I would still recommend the Gen-II to avoid the potential side effects of having to mess with the ECT.

 

[GrizzlyClint]

Maybe I’m missing something, but, can I completely remove the SAIS hardware installing the full gen 2 kit? Less clutter in the engine bay is a desire of mine. Plus with it being bypassed what’s the point in keeping it? Mine is functioning perfectly on our ‘08 470 but I like preemptive maintenance rather than reactionary maintenance.