OMG! I Installed the Hewitt Technologies Gen-II Bypass

OMG was it hard!

First, full disclosure, if a level 1 mechanic is someone who can change their own oil and filter, then I consider myself a level 2 mechanic. Not only can I change my own oil and filter, but I can change brake pads and rotors, but that is about it.

This supposed 1 hour install took me most of the day, and I almost gave up numerous times.

I would highly recommend starting the install by installing the harness first. That way, if you can't disconnect the connectors that attach to the pumps (you can't believe how difficult it is to reach back behind the engine to get to them) and you decide to give up, you don't have to go to the trouble of removing the Gen-II unit and putting the stock one back on.

The main wiring harness for the entire truck is pretty much in your way for the entire install of the AIP harness. There are three small brackets holding the main wiring harness in place. If you loosen those brackets the main wiring harness moves about a half inch (no more than that) and if you have really small hands that are as strong as a linebackers, maybe that extra half inch will allow you to get back to the connector.

That is the other thing, you never actually see either of these connectors. It is done totally by feel. I wasn't even 100% sure I was removing the correct connectors.

Moving on to the block-off plates:

Absolutely, positively go to The Home Depot and buy a wooden dowel about five feet long that you will eventually cut to size. The dowel I bought was in the gardening section and I think it was some sort of replacement handle for a shovel.

Once I got the dowel and cut it to size the plate installation was a piece of cake. The problem was, and this is on me, I tried just about everything else first, before going with the dowel.

In my opinion, all the significant difficulties I encountered were kinda sorta mentioned in the online videos and the written instructions, but, again, in my opinion, they were completely glossed over. The trick using the dowel for the plate install is mentioned in the written instructions, but I don't even think it is mentioned in the video, let alone demonstrated.

I eventually got 'er done, and as far as I know the kit is working correctly, but it was definitely a frustrating ordeal.

One last thing. I was having no problems with my AIP system and I did this install strictly on a preventative basis.

Thanks for letting me vent.

 

Nice job! You got out of your comfort zone and you got it done. I consider myself an average type mechanic so I know where you are coming from.

 

I don't know where I fall on the skill level scale, but those block off plates were a bear. I don't think that I would offer to do this portion of the install for someone else, but merely serve as an "observational consultant".

 

Nice write-up and thanks for the tips.

Not real familiar with the job so I can’t envision the purpose of the wooden dowel.

For the purposes of being prepared in the case I need to do this, would you measure the diameter of the dowel? Perhaps it is on the price label. Or provide the Home Depot product code.


Greg

 

We must have been tackling this job at the same time. To echo it is challenging. The block off plates went on relatively smooth.

Plugging in the harness the the air pumps was daunting and felt impossible at times. I almost gave up. My dad got one side and I got the other but if you don’t have slim hands I don’t know how it would be possible.

no codes and truck ran great after. This was a preventative measure as well. Good luck to all you weekend warrior mechanics.

 

The diameter of the dowel was a tad more than one inch. As mentioned above, I think it was a replacement handle for a shovel.

The written instructions are pretty clear on what to do with the dowel; it's just a matter of going to the trouble to get one and then following the instructions.

 

thanks for the tips

 

Just installed mine and it was a beast. I made the mistake of thinking the block off plates was going to be the hard part so started with that. Turned out to be the easiest by far. Getting the factory harness unplugged from the pumps was a huge challenge. I was 500 miles from home and had no tools

 

What was it about unplugging the factory harness from the pumps that made it challenging? Simply reaching the connectors, disconnecting them, both, or something else. Would a wire plug tool help? Considering buying a tool and wondering if it would help. This is what I am looking at.

$21 Lisle 37960 Electrical Disconnect Pliers

https://www.amazon.com/Lisle-37960-...hasWorkingJavascript.1|hasWorkingJavascript.1

 

When I did my Gen 2 kit the connectors were the easy part I did use a small screwdriver to release the lock on the connector, the block off plates were more challenging especially the driver side one of the nuts was pretty stripped I think the Toyota tech who replaced the system the first time they failed didn’t do the best job

When I did the block off plates I only loosened the nuts to barely slide the plate in and not to completely remove the 2 connections

 

The tool that Steve 6 linked would have helped

 

So, begs the question....how'd ya do the block off plates without tools?

 

I installed the Hewitt system on my 4.6 L and it was an extremely easy installation. All engine components are very easy to get to. As members have mentioned the 5.7 is a little bit of a challenge.

 

I'm currently trying to decide if I should take this on. I have a 2007 Tundra with a 4.7 (2UZFE). Had this issue once already when I was just over 100k miles like 3 years ago (currently at 132k). I was able to get the dealer to fix the problem under warranty the first time, but kinda doubting they will do it again... and the fact that it already failed again means I'm really ready to bypass. Anyone with experience on this particular model engine / truck? Sounds like a real bear (I have big hands) and I'm also worried about the block off plates because I live near the coast and there is a lot of corrosion. It looks like the the Air Tube flanges are accessible from the top of the motor, but the angle of the flange nuts is 'down' and it seems like it will be pretty hard to push on them (with or without a dowel) to open things up enough to slide in the plates. I'm pretty handy but every time I start wrenching on a motor I end up with bloody knuckles and super frustrated. Anyway for now I am just pulling the battery cable constantly to keep it out of limp mode ... just hoping to hear a success story with this particular setup or any tips before I order and go for it...

 

I do not have a 4.7 but did read the instructions you posted and did a 5.7 bypass. By far the hardest part of the 5.7 install is getting to the valves behind the motor, whereas it looks like the 4.7 the valves are very accessible.

Yes the block off plate location on the 4.7 appears to be the hardest part, especially if there is corrosion like you say. My 2007 FJ 4.0 exhaust bolts are ooofta so I can only imagine yours will be tough to remove and may end up stripping, shearing or round the bolts. So my advice is to pb blaster the bolts and attempt to loosen them before you buy the kit. If they loosen and you can get to them then cool go for it, if not then revisit options.

 

That seems like great advice. Thanks man. I like your Bigfoot picture that's awesome.

 

ATF on there for a few days, even a week in advance is good too. I use it for stubborn rusty exhaust bolts. Coat them every day, let it burn off, works great!

 

i did it on my '07 4.7 a few weeks ago and it was pretty easy peasy. the directions were like 90% clear, there were a couple parts that took some figuring out, and then, "ooohhhhhh, i see." the only difficult part was the passenger side block off plates. i had to borrow a couple ratchet extensions from my neighbors to get to it from the wheel well while laying on the ground. there aren't many videos online with the 4.7 so i made one to upload to youtube but never did. i can send it to you if you want.

edit: i uploaded it to youtube. my one and only!

here you go, hope this helps. don't mind my filthy engine bay ¯\_(ツ)_/¯

 

I installed a Gen 1 bypass because that was all I needed for the code my truck threw when it went limp. It’s a 07 5.7. Installing it was easy EXCEPT the block off plates. Somehow during the attempts to get the driver side plate on, the exhaust manifold apparently cracked or came loose to some degree where the block off plate goes on. If you look it up you’ll see others have had this weak spot go wrong as well. Long story short the $155 bypass install coat me $1300 by the time I had to get the driver side manifold replaced ($600 OEM part and then labor). The kits been on with the bypass plates for a few thousand miles and has ran fine, sucks but is what it is…just be extra careful when you are trying to do the block off plates, my two cents.

 

The block off plates on the 07 4.7L install on the top side of engine. Passenger side was more difficult but with patience not difficult. Makes a big difference. Hard to believe the air system was sucking the life out of the engine.