SAIS bypass via tune

Good afternoon everyone, recently I pulled one of the dreaded codes for the secondary air injection emissions system (P2442) on my 2007 Tundra 5.7. I currently have a second vehicle for daily use, therefore I don’t commute in the tundra anymore. For this reason I’d like to bypass the SAIS system as I’ve read they are prone to repeated failure over time and I don’t have money to replace it. I’ve looked at the bypass kit, although I’m reluctant to trust aftermarket parts to keep my truck running properly. I’ve read about tuning via DAP or hptuners, it seems to be the most reliable way to bypass the codes that keep putting it in limp mode. I know next to nothing about tuning and vehicle electronics, is it feasible to block the codes via tuning as someone who isn’t familiar with tuning? I don’t even know what DAP means, assuming it’s a brand? If anybody could provide a walk-through of what I would need to do and if this would work I would really, really appreciate it! I’m almost at 200k and I don’t want emissions issues to keep this truck continuing to sit and gather dust.

 

I'm having the same issue and am installing the bypass kit this weekend. everybody seems to gave good luck with the Hewitt Gen 2, so that's what I got. I'd rather throw a $450 part at it than spend thousands on a mechanic

 

The tune will turn the lights off on the dash, but if someone plugs into and scans the truck they will see the SAIS has failed. The limp mode throttle limits can be bypassed in the tune, at least there's tables for it that I always "turn off", but I've never had someone have the SAIS fail to see if the limp mode is ENTIRELY disabled, so take it with a grain of salt.

If you have to pass emissions and the SAIS will make it fail, then I do not think a tune is able to fix it if the emissions place is thorough. If that is not a concern, then a tune will conceivably be able to fix all drivability and dash light annoyances.


In regards to the tuner, that may be its own cluster and probably not cheaper than the Hewitt kit. DAP was a tuning company/individual that no longer exists. OTT is the big name but I think they refuse to touch anything related to emissions. If there's a local place/individual with HP Tuners or VF Tuner they could quickly go in and turn it off, but it'll cost at least $200 to unlock the ECU to tune it. You could do it yourself, but then you're in $600 between the $400 flashing hardware and the $200 ECU unlock.

 

I had p2442. It wasn't permanent yet so I over rode the system check. I did the DIY AIP bypass where it says it a good temp, installed block off plates and disabled the non electrical codes. I already had hpt so based on what @snivilous stated. You need the Hewitt system to totally bypass it (the drivers and front pumps).

 

this guy SAISes

 

I did the diy version a dozen years ago on my 08. It's been fine and trouble free for almost 200k miles. It was at 50k miles when I did the diy version.

It's pretty simple. If you can solder or crimp wires, you can do the mod for less than $40.

The only issue you may have is you need to know if the truck ever had the modules reflashed.

Toyota changed the programming so the pumps would randomly cycle when the truck was parked.

You need to find out if the truck got the reflash.

You can check be going to Toyotaowners.com, enter your VIN and you will see all the service that was ever perform at any dealership.

 

Did you ever do anything???? In the same boat....

 

You can do it for the cost of the block off plates and the DIY kit. As long as your valves aren't stuck open.
This works for 2007-2009:

 

The P2442 code i have says: Secondary air injection system switching valve stuck open bank 2....

 

Does it clear after scanning?

 

Yes, if i clear it, but comes back after 1 to 3 days.

 

that's fun

 

Did you read post #6? I posted a diy aip bypass that works for 07-09 without the reflash. You need to do either the Hewitt or DIY bypass before it ruins the valve then it'll need to be replaced.

 

i got it now....thanx (from post #8). i can do it, but then the blockout plates are still necessary....?

 

For it to be complete.
Another option that is supposed to work with ecu's that weren't re-flashed is the
https://rutechsolutions.com/collections/aip

It had decent results for the 2007-2009 tundra.

 

I'm pretty sure my valves have been inoperatable for the last 14 years.

I did the DYI version around 2013.

I forget I even have the mod running. I'm presently 800 miles from home running the truck every day. My un flashed 2nd gen just runs just fine.

I never did bother with the block off plates. I was pretty sure I had a bad valve, so I thought the point of protecting the valves was useless.

Going by memory, I thought failed pump(s) sent you into limp, bad valves just triggers a CEL. Been a while since I dove deep into this useless system.

FWIW, I live in non emission check state, so I don't have the worry about an annual ECU check.

 

We stopped with the emission checks here too. I thought it was valves were limp mode as I ran with my pump unplugged. But I forget...haha

 

I guess I got some testing to do.

On my '21 I have a code for a failed pump. I'll just run it to see if it goes to limp mode.

I've been clearing the code every time I get into the truck so I can't be 100% sure it's pumps or valves that cause the limp mode.

Presently driving the '08 during the winter months. It runs just fine with the DIY bypass.

 

If you need a set of pumps...I had them disconnected and finally took them out. A 10000k 5volt resistor tells the ecu they are there and off. I believe the newer ones run randomly. On the ecu wants to see min of 8v less 1ohm or something when on. So that Hewitt kit does it all.

 

I removed both my pumps on my '21 and bench tested them. Both spun up just fine when 12 v was applied.

The code tells me bank 1 pump off. I wanted to test the proving switch, but the cock suckers at Toyota used a security Torx bit, so I couldn't test the switch. My mistake. Reinstalled to have the same code pop the next day.

I've either got a bad switch or a cut line between the pump and the driver.

I guess I'm pulling that fender liner again.

Thankfully I got lots of plastic darts to re secure the liner and mud flap.

That's a May job.

 

Yeah, i checked that Rutech out a bit on utube....very simple plug and play....much easier connection than the Hewitt....don't even have to blindly reach down behind the engine to unplug/plug into the secondary air injection pump control valve. cheaper at $190. however, i'll try the DYI you posted first.

 

Mine triggers a CEL and vsc and 4lo flashing....i don't think it goes into limp mode, but it does cut back on acceleration power....maybe like tow mode?
i'm glad to read that you went without the block off plates cuz i was worried i might not be able to do it....(and, i don't have them).

 

Are the 5.7 blockout plates different size than the 4.7? Or are they both like in this attachment?

 

Just an FYI, OTT won't tweak tunes to "violate" emissions laws.

 

Love me a good violation

 

UPDATE....i did the dyi bypass as outlined here: https://youtu.be/dmHEE52BW28?si=28hDpmJK46EJ-oQR and after 3 weeks its been perfect. i have not done the block-outs as of yet.

 

That's the same one I've been running since 2013.

 

Nice! I had the sai valve stuck open code and all the internet 'wisdom' says its necessary to to put the block off plates or the 'valves' will be burnt/ruined....Like you, i'm thinkin the valve is already ruined....

 

I don't have the plates anymore as I removed my airtubes. If your valves were stuck open the exhaust could ruin the barometric sensor the ecu needs to measure. That is the main reason for a plate. Why you need to know if it's stuck open.