06/07 Air Induction Pump Failure & Bypass (1 Viewer)

[OEMGUY0720]

I got my kit today:

The installation instructions print out say to tap the wire on the “ST” or “STA” or a violet/purple relay, but I don’t see that on my relay box?

V3647H Kit, I have a 2006 LX

 

[jerryb]

I'm not sure why they just didn't write starter relay in the instructions.

edit,

forum.ih8mud.com/threads/p1442-p1445-secondary-air-intake-advice-needed.1089150/post-13545739

 

[OEMGUY0720]

I'm not sure why they just didn't write starter relay in the instructions.

edit,

forum.ih8mud.com/threads/p1442-p1445-secondary-air-intake-advice-needed.1089150/post-13545739

Thanks @jerryb ! So it looks like the correct terminal to use is terminal 2 on this photo? (which is on the 9-o’clock position from @Smobien ‘s picture).

@hewitttech

 

[jerryb]

Your relay is backwards. In the pic I mean. Its 3 in your pic.

edit, but now after looking I don't know if matters, 2 or 3. regular relay or not idk

 

[J1000]

I did headers today. Just got the standard headers and a Hewitt kit and I'm doing the permanent SAI-delete.

I plugged all 8 SAI holes in the cylinder heads with 3/8-16 x 1/2" set screws and used high temperature ceramic threadlocker to keep them in. I saw this done on the Toyota 2ZZ engines. It was really easy to tap all of the holes, no issues at all. I got two taps so I used a fresh one on each side. Also used a socket tap extension to be able to get good leverage on it.

If you are doing headers and SAI delete anyway, then save the $400+ and get the 98-05 headers without SAI.

Set screw plugs: https://amzn.to/3ke65cf
High Temp Threadlocker: Amazon.com: Vibra-TITE 19960 Hot-Lock Extreme High Temperature Threadlocker, Translucent : Automotive - https://amzn.to/3bP1BEd
Bosch Tap: https://amzn.to/3wqXNTi
Socket Tap Extension: https://amzn.to/30aXCzv

 

[OEMGUY0720]

Your relay is backwards. In the pic I mean. Its 3 in your pic.

edit, but now after looking I don't know if matters, 2 or 3. regular relay or not idk

I finally got a reply email from Paul Hewitt, and he confirmed that I need to use any of the smaller pins on the 06-07 starter relay (pin #2 or pin #3 on the photo below).

Yes that block plate is interesting to install (add lots of cussing and what a better way to do when the AHC is on Low )

Block off plate on point using a pry bar. (this is on passenger side but same thing I did on the driver side)

 

[OEMGUY0720]

Question for those who has the hewitt tech SAIS Bypass kit installed:

Is it just me or it’s a normal/expected effect after installing the module with block off plate that the fuel consumption got better? Normally at 3/4 on the fuel gauge I would’ve driven it 60-70 miles. It’s now at 110 miles and still at 3/4. This is 100% 30-45 mph zones driving only, no freeways. Weird and interesting.

 

[04UZJ100]

Question for those who has the hewitt tech SAIS Bypass kit installed:

Is it just me or it’s a normal/expected effect after installing the module with block off plate that the fuel consumption got better? Normally at 3/4 on the fuel gauge I would’ve driven it 60-70 miles. It’s now at 110 miles and still at 3/4. This is 100% 30-45 mph zones driving only, no freeways. Weird and interesting.

Weird that a government mandated system is costing you money??? No way.

 

[jerryb]

Its just u. But the trace on the fuel sender is dirty as F. That could easily stick or quit working.
Maybe you should quit driving upside down.

 

[kwon-offroad]

Just installed mine yesterday and will report back, as we head to the cabin and mpg up and down is pretty consistently on the same mark.

Install was a cinch. 20min on my back on the crawler. LC on H, stubby 10mm on a swivel with super long extensions and a 18" pry bar. One person and one banana job.

 

[OEMGUY0720]

Its just u. But the trace on the fuel sender is dirty as F. That could easily stick or quit working.
Maybe you should quit driving upside down.

I just replaced the fuel sender assy less than 5k miles. Okay maybe it’s just me

 

[hewitttech]

Wasn't getting messages again because the forced PW reset and didn't get that email either. I will get the LC/LX starter relay instructions finished this has been on my lost forever.. I appologize.

 

[J1000]

My MPG also bumped up a little bit. Could be because of leaking headers I replaced at the same time too. But yes a leaking SAI system could definitely lower MPG.

 

[hewitttech]

If you were in limp mode your mpg will suffer. The engine is not running in closed loop fuel control. Getting out of limp mode will let it go back into closed loop fuel control where it is tuning itself again.

 

[J1000]

If you were in limp mode your mpg will suffer. The engine is not running in closed loop fuel control. Getting out of limp mode will let it go back into closed loop fuel control where it is tuning itself again.

Even in closed loop if there are e exhaust leaks then the engine will use more fuel.

 

[hewitttech]

Even in closed loop if there are e exhaust leaks then the engine will use more fuel.

Yep. Any leaks between the engine and A/F aka upstream O2 sensors will cause it to run a bit rich and burn more fuel than necessary. All the tune up items even including cleaning or new O2 sensors can make a huge difference. So can running Techron through it to get rid if carbon buildup as that greatly contributes to timing retard in these engines.

 

[kpz1234]

Thanks much for this info, you saved me $2k, and I ordered from Hewitt Tech!

 

[gold99xx]

I have a question about the Gen1 KIT on a 2006 LX470 123,000 miles. P2445, Cold weather starts, Please Please help...

Here is the story. I live in NE and have cold mornings etc. nothing out of the ordinary. About a month ago I drove the car about two miles, under 35 MPH, parked it. I went for a walk for an hour and came back and when I started it I got my first ever CEL VSC etc and the car went into limp mode. I unplugged the battery to clear the codes and went to the forums. I bought and installed a GEN1 and a code reader and everything was fine for about 100 miles, now as I was driving on a cold morning the lights came on again ( while driving toward 50MPH, etc, NOT on START, unclear if it went into limp mode because the return journey was all downhill until my driveway ).

I called Hewit and spoke to a rep that suggested I unplug their kit from the MAF and return it to stock while leaving in the block-off plates. I was given two codes to look out for P2441 and P2443. I reset the CEL and drove it again, this time I again drove about 100 miles with no issues, two days ago I drove about two miles under 35MPH, left the car for an hour to take a walk, and when I came back and started the car the CEL, etc came on. I read the codes and it was a P2445, Hewit was nice enough to send me another unit because it was around Thanksgiving and if the P2441 and P2443 came on I was advised to change the unit because this meant the unit may be faulty. Since it was the P2445 code I didn't change the unit and called Hewit today.

I was advised it may be the ECM glitch and to start the car run it for ten minutes and then shut off and restart the car. While this seems like a minor inconvenience, I know I may not be able to stick to this ( family, dogs, life, etc ) I also do not want to keep clearing the code with my scanner. Has anyone else experienced this and does anyone have any thoughts or solutions? It would be greatly appreciated. I do know that if I replace the SAIS this may happen again etc. Just to reiterate that I got the P2445 on both a cold start and while driving, so this is what is confusing me.

Any suggestions or things I can try other than start, restart, or driving around with a code reader would be helpful. I am not averse to spending some $$ to fix this so that the codes don't come back, it is my daily driver and my commute is a freeway for about 140 miles each way. Obv I want. to avoid LIMP mode while on the freeway at all costs. And please NOTE any work beyond the GEN 1 install and the block-off plates would be done by a local mechanic.

Thank you ALL

 

[jerryb]

my advice... Stay after them for some kind of fix. I continually get 41, 42, and 45s and I have the gen 3.
While our installs and circumstance are completely different this shouldn't be a THING for either of us.
Yours should be even easier to pin down, and the money you spend should guarantee that.
Not a response like, we had a bad batch, or second batch is good when it isn't, wiring bad, etc.
I'll get some s*** for that I'm sure. But for the money, for 2006 and 7 LC or LX, the gen 3 does not work in multiple examples with components removed or not removed.
Stay with gen one, the 150 dollar version, and if it's like the 3 years ago version it should be good to go. Never mind that money might be needed for vacuum lines, valves, or sensors. All that stuff needs be functional.

safe mode on the freeway isn't a big deal. You do need to pull off and reset though. It's not like no brakes, no damage is occurring when it happens. Use a BT reader.

IF I lived in a cold climate I'd be calling Hewitt everyday. I don't care to waste a year looking for cold days here and there to recheck drivers or codes.
The LX and LC sai versions are different without a doubt compared to tundra etc.
I'm over it.

 

[hewitttech]

I have a question about the Gen1 KIT on a 2006 LX470 123,000 miles. P2445, Cold weather starts, Please Please help...

Here is the story. I live in NE and have cold mornings etc. nothing out of the ordinary. About a month ago I drove the car about two miles, under 35 MPH, parked it. I went for a walk for an hour and came back and when I started it I got my first ever CEL VSC etc and the car went into limp mode. I unplugged the battery to clear the codes and went to the forums. I bought and installed a GEN1 and a code reader and everything was fine for about 100 miles, now as I was driving on a cold morning the lights came on again ( while driving toward 50MPH, etc, NOT on START, unclear if it went into limp mode because the return journey was all downhill until my driveway ).

I called Hewit and spoke to a rep that suggested I unplug their kit from the MAF and return it to stock while leaving in the block-off plates. I was given two codes to look out for P2441 and P2443. I reset the CEL and drove it again, this time I again drove about 100 miles with no issues, two days ago I drove about two miles under 35MPH, left the car for an hour to take a walk, and when I came back and started the car the CEL, etc came on. I read the codes and it was a P2445, Hewit was nice enough to send me another unit because it was around Thanksgiving and if the P2441 and P2443 came on I was advised to change the unit because this meant the unit may be faulty. Since it was the P2445 code I didn't change the unit and called Hewit today.

I was advised it may be the ECM glitch and to start the car run it for ten minutes and then shut off and restart the car. While this seems like a minor inconvenience, I know I may not be able to stick to this ( family, dogs, life, etc ) I also do not want to keep clearing the code with my scanner. Has anyone else experienced this and does anyone have any thoughts or solutions? It would be greatly appreciated. I do know that if I replace the SAIS this may happen again etc. Just to reiterate that I got the P2445 on both a cold start and while driving, so this is what is confusing me.

Any suggestions or things I can try other than start, restart, or driving around with a code reader would be helpful. I am not averse to spending some $$ to fix this so that the codes don't come back, it is my daily driver and my commute is a freeway for about 140 miles each way. Obv I want. to avoid LIMP mode while on the freeway at all costs. And please NOTE any work beyond the GEN 1 install and the block-off plates would be done by a local mechanic.

Thank you ALL

Unfortunately there is really no other options. You can try to completely replace the system with factory parts as the current service bulletin says but time and time again I have still seen the freezing temperature glitch persist so do not recommend wasting your money. There really just isn't another solution other than finding the old TIS limited service campaign information so you can update the ECM and this has been a dead end year after year. For several years we had hoped a solution like our Gen2 kits would be able to possibly get around the ECM glitch but even they cannot get around the problem. Currently the only way around it is the warmup above freezing and restart before hitting 50mph in that first run cycle.
You don't have to let it warm up for 10 min and then restart it before driving. You can start driving it cold and as long as you restart the engine before you hit the 50 mph mark and the engine is now above freezing the glitch won't happen. I know this is not exactly what you are looking for but it may make it a little easier to deal with. As soon as initial engine (cold soak starts only) temperatures are above freezing the problem goes away. Again this is only something you would need to do once it has positively been identified as the freezing temperature glitch and only for that first run cycle.

We do occasionally run across this where the problem is both the failing air system and it is also on a vehicle that has the freezing temperature glitch.
To clear up your confusion about how the code can come on at startup and while driving there are 3 ways the P2445 code can come on.
It is not normally possible to get the P2445 code on startup AND have the freezing temperature glitch as the case requirements are different.

1) The normal reason to get a P2445 code is a failing secondary air pump. The system will only normally be commanded to operate on a cold soak start when the engine has been off for 7hrs or longer and the initial engine temperature is above 40F. This is the normal version the bypass kit can prevent because it stops normal operation of the system. It sounds like you had this or valve stuck open codes before you installed the kit which is why you initially had the codes on startup.

2) A damaged pressure sensor. This is rare for a 4.7L three valve configured system but it does occasionally happen. Normally this would exhibit itself as a P2445 code that comes on at random and not tied to startup, freezing temperatures or speed. It is also the second cuase of a P2445 code that cannot be cleared at all with the first reason beign a blown air pump fuse. Likely not your problem but a possibility if your P2445 doesn't match reasons 1 or 3.

3) The freezing temperature glitch which was documented by Toyota well over a decade ago there was a limited service campaign at the time to fix it. This is an extremely specific case for the glitch and and there is currently no actual fix for. Because of the specific conditions required for the glitch to occur it should not be possible to get the freezing temperature glitch as well as a normal p2445 code (case 1).

I have worked on this problem extensively with active and former Toyota Technicians and can confirm the service bulletin existed as I found it myself in TIS 8-9 years ago but did not know they expire and get deleted. Since then I have not been able to find a copy of the service bulletin. The techs I was working with remember performing the work but at the time TIS was done by CD media and even with help have been unable to track down a copy. The service bulletin is the only known possible way to actually fix the freezing temperature glitch. We try to make sure all of our customers are aware of it as there simply isn't' a permanent solution for it.
We have COMPLETELY removed every component of the system from the vehicle as well as replaced all components of the system with brand new factory Toyota parts and the cold weather glitch will still happen.

I question it year after year and exhaustively come to the same conclusion that confirms the original service bulletin that I saw that states it is in fact just a glitch in the ECM software. I make sure that if they have a customer on the phone with an early 4.7L that they are made aware of the possibility of the problem as well as mention it on all of our product listings. There is also a large write-up explanation here on our codes page under P2445: https://hewitt-tech.com/codes/ (the text markup isn't as good as it used to be on our new website as it was our old site yet) Please read this if you haven't already.

If you have any specific questions please PM me or call and ask to speak to me directly.
Paul Hewitt