Check engine light, yay!

The bypass doesn't always play nice with other pickback systems such as the URD MAF calibrator. Left alone, it should be fine.

 

@shifty` We appreciate your endorsement and understand your hesitation. I agree, introducing a Bypass can sometime complicate the issue and add additional variables. I also want to thank you for recognizing our customer service, Hewitt takes great pride in serving our customers. That said, we do are best to help troubleshoot and resolve any issues customers may see after installation.

@Solid Snake If you have any questions at all please do not hesitate to contact us. Happy to walk you through the Bypass options or provide more information about the SAIS.

 

@DJenerated I will agree the Gen 1 Bypass Kits are not engineered to work with other systems manipulating the MAF or ECT readings. However, the Gen 2 Bypass Kits emulate the SAIS and avoid many of these complications because it does not install at the MAF. Of course I do want to state that we have not tested our Bypass Kit with all the Tuners or Pickback systems on the market. That said, the Gen 2 Bypass Kit hooks up at the Air Injection Driver and Air Switching Valves; in theory should not interfere with other aftermarket mods as you have mentioned.

 

Thank you for clearing that up. I knew there were different bypass gens, but I couldn't remember what made them different.

 

If memory serves, the 2nd gen requires degloving a small section of three wires and soldering onto them at/near the ECU. I think the 1st gen piggybacks out of the fuse/relay box in the engine bay, and intercepts at the MAF, no-solder. But @HewittTech01 can probably clarify on that. EDIT: Actually, differences from them are here and some other details here.

@Cummins3500 showed the 2nd gen kit install process here in 1st Gen forum. There's another thread, from a 1GT owner who installed the gen2 and kept tossing 'stuck valve' codes after, but I can't find it, I guess it might've been deleted. Most common issue reported here on Tundras.com with the Gen2 kit is P2440 (stuck valve), for both 1GT and 2GT trucks, but there's a process to help resolve. This is something else to note regarding some stuck valve codes, but may not pertain to all.

I appreciate the simplification in Gen2 Hewitt kit. One big hurdle for 4.7L owners to clear is dealing with the blockoff plates. Some folks had trouble breaking the old ones free, fasteners snapping off, etc.

@wandering_boy did a great writeup on SAIS.

Based on feedback I've seen, I'd definitely go with Hewitt vs. the Rutech kit. But yeah ... YMMV. Not always a silver bullet, even if you choose OEM replace.

 

Yeah I have the Gen 1 plug n play kit. I didn't use the block off plates because my SAIS functions fine otherwise. I only needed the bypass to run the older, cheaper non vvti JBA longtubes

 

Just noticed something else cool.

I saw someone post online they'd give you 35¢/gallon off your next fill-up if you link your Advance Auto Parts SpeedPerks account (which is free) to your Shell Rewards account. Thing is, I didn't have a Shell Rewards account officially, Advance Auto somehow had my phone number registered in Shell's system but not tied to an account.

So I figured "WTF", and setup a Shell Rewards account. Then linked it back to Advance Auto using the number Advance gave me (427 with your 10-digit ph#) and they actually gave me my 55¢ off my next fill-up. Hell yeah!

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2.89 a gallon!!!!!!! Wow that is dirt cheap!! That’s cool I’m almost at 5$/gallon

 

@shifty` I agree the installation for the Block off Plates '05-'06 only (VVT-i models) is not fun. Alternatively you can install the Block off Plates at directly at the Check Valves along the fire wall but that usually requires the removal of the intake. That said, any new model 4.7L Tundras the Block off Plates are much easier to install and that 2 Gen Bypass Kit is Plug & Play. They install direct at the Air Switching Valves which are accessible through the hood on either side of the valve cover.

 

Got my truck back from the shop yesterday. They replaced the SAIS pump and valves. In the parking lot, CEL came back on. They checked for codes and didn't find any, reset the light. They told me if it comes back on, bring the truck back and they'll get me right in. Welp, it came on this morning. I checked it and got P2445. Ugh...

 

I wanted to 'Like' this just because I like when people update, but the reality is, it's not exactly 'good' news.

The positive? You didn't do the work, the shop has to make it right, and ... you don't need to question whether anything non-OEM is causing the issue.

 

@Solid Snake Just wanted to say make sure if they are making any repair Factory/OEM is the only way go. Aftermarket parts are cheap for a reason and more failure prone the original. That said, I wanted to mention a know Freezing Temperature Glitch on Older 4.7L engine size. It only happens under very specific circumstances but will trip a P2445. If you see this code tripping outside of the parameters then mostly like Mechanical or Electrical failure.

• Has the weather been in the 30’s and 40’s at night or in the morning?
• Was this CEL tripped on the first drive cycle of the day?
• How fast were you going when the CEL came on?
• Did it throw you into limp mode?

If the weather has been colder, and the 2445 was tripped on the first drive cycle when you were approaching 40-50 MPS then It is possible your experiencing the cold weather glitch Toyota has reported in some older 4.7L models. I have included some additional information below regarding the cold weather glitch. Unfortunately, this glitch is in the computer programming and out bypass kit will not address.


*On some 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.


However, there is a work around. This glitch should only happen on a cold start (7 Hours since last start) on days when the temperature is near or below freezing. For some reason when the truck gets to 40 – 50 MPH on that first drive cycle it will trip the check engine light and throw the truck into Limp Mode. We recommend on days when temperature is near or below freezing to warm up the car for about 5 minutes until the temperature gage starts to rise on the dash. Then turn off the vehicle. This will terminate the first drive cycle and should prevent the glitch from occurring.


Please keep an eye on this and keep up posted if this resolves the issue. This is a difficult explain via email but if you need additional clarification please give us a call,

 

It may have got into the 40s last night. CEL came on right when I started the truck this morning. It did not come on yesterday when I was driving home from the shop (about 4 miles).

 

There is a TSB for the freezing weather P2445 code. Info on that is over here: https://static.nhtsa.gov/odi/tsbs/2012/SB-10075945-0699.pdf

(attaching PDF just in case...)

 

Just called the shop to let them know what's going on. They said bring it in and they'll make it a priority. Hopefully that means I'll get it back tomorrow. I'm getting tired of driving my dad's Kia Sol.

 

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Just curious why not bypass? So much easier and cheaper. And the stupid SAIS is so failure prone.

 

I guess I'm just a masochist.

 

I dunno, I still think it's the smart thing to do, for reasons already discussed in this thread. Don't beat yourself up.

 

I am bypassed but not with any kits. Wires Soldered into my harness and connects to my fuse box.

 

You bypassed your SAIS without using a kit? How does that work? What provides I/O to the ECU if there's no embedded device at play?

 

I’ll pm you

 

Okay....just dropped the truck off again. I told them the code I got was for the pump. He told me that they installed a new pump but it was having issues, so they got another pump and put it on. He said this supplier must have a bad batch or something, and if the pump is the problem, they'll order one from someone else.

 

Because he doesn't listen to us

 

I was thinking a shorter M word

 

If you just want it how Toyota designed it, it that's fair. I was just curious. And it sounds like the shop is doing the right thing so that's comforting.

 

That's pretty much it.

 

Update @shifty`

After bringing my truck back, they got it right in the next morning. I went up there today to pick it up. They told me that the pump they put on was bad, and it was a Toyota pump. So they ordered another pump, and valves, and just went and replaced everything. After replacing everything, they held onto it for another day just to give it a few test drives to make sure the CEL didn't come back on. All is well now.

 

Thanks for the update!

 

Awesome, didn't they replace the valves the 1st time? IIRC (without scrolling up to see the code), the most recent code was a stuck valve. If they didn't do anything with the valves the 1st time, that may've been the problem.