P1440-P1443 code after Hewitt Tech SAIS Bypass (1 Viewer)

Joined
Sep 14, 2020
Messages
9
Location
greensboro, NC
Hello all! I bought a 2006 lx470 in October knowing that there was a p2445 code on the vehicle. Knowing it was the SAIS system, I immediately bought the Hewitt Technologies full bypass kit including the block off plates. Vehicle drove fine but then threw a p1613 and I called Hewitt tech and diagnosed. P1613 stopped. Truck then threw a p0420 oxygen sensor code. I drove with that code popping up sporadically for a few months. I could clear and it would not come back on for a few weeks. I was really just testing system to make sure it was truly just that code. Vehicle drove fine during that timeframe.

After a few months, I Had new oxygen sensors, spark plugs, pcv valve, and serpentine belt, installed a couple of weeks ago and vehicle drove great for 5 days with no codes.

Then on startup in afternoon on Monday of this past week after driving in morning, it threw P1440 and p1443 code. They are supposedly for the SAIS switching valve circuit bank 1 and bank 2. Called Hewitt tech back and we diagnosed and pointed to thinking it was their AID module or wire loom. They sent me a new one, installed new AID and wire loom this morning with new soldering at ECM and no code at initial startup but then threw p1443 code after about 5 minutes. Car idled great during first 5 minutes until it threw the p1443 code. Tried to drive short distance and also threw p1613 again randomly one time.

I can not clear codes as they just come back immediately. The only time it doesn’t is if I unplug the Hewitt tech bypass kit plugs from the switching valves on top of passenger side of engine. Then code does not come on.

I plugged back in Hewitt tech kit and went for a drive with the code on. While driving the vehicle idles very rough and is sluggish in the short 2 minute drive I took. Obvious rough running and misfire feeling while driving.

I am at a loss for what it is and need some suggestions. Hewitt tech is closed on the weekend and we have already been without this daily driver for almost a week waiting on the Hewitt tech bypass replacement.

Hoping to get some ideas or feedback on what I can try next before next week. I am obviously considering towing it back to shop that worked on it with new spark plugs, oxygen sensors etc. but it just seems strange it drove great after i got it back from them for 5 days.

Thanks in advance!
 
Joined
Nov 4, 2007
Messages
10,560
Location
Colorado
I can't help with the Hewitt block off system, as I don't use block offs.


But did you get DTC P0420 before installing kit?
 
Joined
Sep 14, 2020
Messages
9
Location
greensboro, NC
I actually got that code after installing the system. That was what triggered me to replacing oxygen sensors.
Couple of additional diagnosing items.

1. When I plugged SAIS switching valves back into OEM plugs (no Hewitt bypass plugs) no error codes come on but car still idles rough.

2. Exhaust smells heavy of fuel while engine idles rough.

3. I let vehicle sit for a few hours today to let engine cool and then started engine. No code p1443 until after ~85- 90 seconds of the engine idling. Engine idles smooth until around 60 seconds.
 
Joined
Nov 4, 2007
Messages
10,560
Location
Colorado
Make sure all vacuum lines are connected and sung, Including those to A.I. VSVs on RH side of intake manifold and two on power steering pump idle up control up to intake manifold and air pipe. Also check ECT (engine coolant temp) is ~187F.

Make sure no air leak at either end of tube connecting exhaust manifold to #2 A.I. switch bk1 and bk2, particularly bk1

If somehow A.I. bypass wiring is keeping ECM from giving or get proper signals, I've no ideas.
 

jerryb

Supporting Vendor
Joined
Jul 30, 2016
Messages
2,266
Location
pensacola fl.
I hope you get some good advice from Hewett.

I'd go through everything a second time.
Could you please update on what he says?
I'm getting ready to install one.

did you take the manifold off and remove the pump etc?
 
Joined
Sep 14, 2020
Messages
9
Location
greensboro, NC
Make sure no air leak at either end of tube connecting exhaust manifold to #2 A.I. switch bk1 and bk2, particularly bk1

If somehow A.I. bypass wiring is keeping ECM from giving or get proper signals, I've no ideas.Make sure all vacuum lines are connected and sung, Including those to A.I. VSVs on RH side of intake manifold and two on power steering pump idle up control up to intake manifold and air pipe. Also check ECT (engine coolant temp) is ~187F.
Make sure no air leak at either end of tube connecting exhaust manifold to #2 A.I. switch bk1 and bk2, particularly bk1

If somehow A.I. bypass wiring is keeping ECM from giving or get proper signals, I've no ideas.
Thanks a ton for the reply. Just to make sure I understand when you say vacuum lines to steering pump. What are those? I didn’t think this had anything to do with the problem but the shop that did all of the spark plug work etc, also replaced my steering rack and flushed steering system. Wondering if that has anything to do with it. So there are vacuum lines going to steering pump? I didn’t realize that.

My engine runs at like 192-195 degrees. Has been pretty stable but does run up to 200 degrees up hills and higher rpms. Then comes back down after.
 
Joined
Sep 14, 2020
Messages
9
Location
greensboro, NC
I hope you get some good advice from Hewett.

I'd go through everything a second time.
Could you please update on what he says?
I'm getting ready to install one.

did you take the manifold off and remove the pump etc?
I will have to call them on Monday because everything I have done this weekend was basically replacing their bypass kit for a second time and I hate soldering on wiring at ecm twice.

just really strange that when their entire bypass is connected but I just swap VSV plugs to OEM plugs the code stays off but engine still runs rough.

it just seems like I have some vacuum pressure issue that is staying either open or shut once engine warms up and it creates a rough fuel burn process.

I will keep you posted as I talk to them on Monday.

no I did not remove intake manifold to remove pump or any components.
 
Last edited:
Joined
Sep 14, 2020
Messages
9
Location
greensboro, NC
I am having my vehicle towed Monday to shop that did all of the most recent work to see if they can run through spark plugs, psv valve, steering, vacuum lines etc. just to have them make sure it wasn’t anything they did.

truck ran great before, just had code p0420 pop up occasionally.

does anyone think it could be the evaporator system? I have heard code p1443 could be that but have no idea.

Also could it be bad gasoline? what does bad gas or wrong octane gas do in these 100 series?
 
Joined
Nov 4, 2007
Messages
10,560
Location
Colorado
Vacuum lines. Idle up


IMG_0677c.jpg
002c.jpg
 

jerryb

Supporting Vendor
Joined
Jul 30, 2016
Messages
2,266
Location
pensacola fl.
bad gas or water contaminated gas should get you a stutter and random misfire codes.

I'm not seeing a relation between the 16xx - 14xx codes and the bad idle/stumble.

certainly there is a voltage issue somewhere. (AID>ECM) But their driver box is closed so there's no telling what's inside -so no real testing.

not getting the 14xx codes means voltage is good on those two brown valves. Or at least it's reported as good.

the 420 and 30 aren't going to have anything to do with the bypass.
Unless your plates are loose. But you'd be able to hear that leak easily.

Hewett knows more than we do obviously, so hope he gets you some info tomorrow.

I'm installing mine tomorrow and I was going to remove everything. WAS..
 
Joined
Nov 4, 2007
Messages
10,560
Location
Colorado
I agree with Jerry here: Water Gasoline has been a problem this last year more than we'd normally see. Along prolonged sitting, condensation accumulates in the gas. So this must be considered. Possible some Fuel additive then driving through the tank you have, after verifying no vacuum leaks. May clear up running issues.

Since it drove great after shop tuned, not likely they created issues.

Seems very likely a short created, during kit install.

Also possible you have clogged CAT, and it was clogged before you purchased. That the issue PO sold for, was more than just P2445.
 
Joined
Sep 14, 2020
Messages
9
Location
greensboro, NC
I agree with Jerry here: Water Gasoline has been a problem this last year more than we'd normally see. Along prolonged sitting, condensation accumulates in the gas. So this must be considered. Possible some Fuel additive then driving through the tank you have, after verifying no vacuum leaks. May clear up running issues.

Since it drove great after shop tuned, not likely they created issues.

Seems very likely a short created, during kit install.

Also possible you have clogged CAT, and it was clogged before you purchased. That the issue PO sold for, was more than just P2445.
Clogged cat definitely crossed my mind. I have not ever had one so not sure how it feels or reacts when it happens. If it was a clogged cat, wouldnt it throw a "after" cat o2 code? Rather than a VSV code?
 
Joined
Nov 4, 2007
Messages
10,560
Location
Colorado
Clogged cat definitely crossed my mind. I have not ever had one so not sure how it feels or reacts when it happens. If it was a clogged cat, wouldnt it throw a "after" cat o2 code? Rather than a VSV code?

You did show P0420 (CAT Bk1 code). But I'm not thinking CAT so clogged, that it has much to do with current rough running. But I've some doubt replacing and O2 cleared the issue, unless O2 tested bad. What brought up PO420 in first place, if a true PO420 did accrue. It is almost always sometime up stream. The "what" caused always needs found and correcting.
If minimally clogged CAT, it may have cleared itself. A high RPM run for 7 minutes or so works wonders depending on what clogged it.

The VVT engine has one place that with age, we get a vacuum leak other than obvious vacuum lines. It's the intake manifold (IM) gaskets. With these I look for gunk build up on IM tubes coming up from heads. Oil from PCV will seep out during cool down and capillarity action draw up the outside IM tubes.

Seems you multiple issues going on. I feel the A.I. block off kit needs corrected first. I've some concerns you a short at ECU. I'd sorted out first, with Hewitt's help.

Gasoline. Well, if buying gas at old station (old storage tanks), cheap gas or just not driving much, water in fuel is issue we see a lot these days.

If you do end up pulling intake manifold for any reason. We should talk before hand.
 

jerryb

Supporting Vendor
Joined
Jul 30, 2016
Messages
2,266
Location
pensacola fl.
if / when you get info post it of you could.

I was maybe going to leave the pump and valve removed from under the manifold and leave the pressure sensor in place.
But since your thread I'm thinking I clean it all back up and put it back with all three plugged in- just in case.
I guess there really isn't a need to remove the two removeable items altogether.

AIP removed clean intake.jpg
 

jerryb

Supporting Vendor
Joined
Jul 30, 2016
Messages
2,266
Location
pensacola fl.
@wilcoxoffroad
Did you ever have any resolution with your issues?

Twice I've got the 1613 codes since March 20th or so.
I think there's some parameter or a certain condition not accounted for in their driver.
Very difficult to narrow it down. If not impossible.
 
Joined
Sep 14, 2020
Messages
9
Location
greensboro, NC
Good morning Jerry! @jerryb Apologies for the delay in posting final solution but it took my friends shop over a month to figure out what was going on. Even when they thought they got it solved, we both said, "lets drive it for a few weeks to make sure". I am now on my third to fourth week of driving with no codes (knock on wood).

Here is what we found. I am summarizing a ton of back and forth with the shop so please ask specifics if needed.

At the point my truck went to the shop, I was already on my THIRD control module from Hewitt Tech that I installed myself and also put in two HT wiring harness to make sure it wasn't the wiring. Never would have guessed I would have been on that many modules and it initially surprised me because I thought there is no way it can be the HT module after 3 different ones. However, the shop did a ton of diagnosing and after multiple calls with Hewitt Tech Technicians on the phone; they narrowed it down to thinking it was STILL a bad HT control module. They tested plugs at valves, ohms, etc. (re-soldered connections also just to make sure it was clean at the ECU).

After calls with HT technicians, HT confirmed the module serial number to be in a "BAD BATCH" of modules that they received from their manufacturer. I think I went through 3 bad batch modules unfortunately. Again, I thought there was no way they were going to send me a FOURTH module and have that be the problem. Regardless, they said that they wanted to send us a confirmed GOOD module to make sure they took that off the plate of being the problem. During that time, the codes that popped during each "old" module test showed a different code which didn't add up and added to the fact that they thought the module was creating some of the problem.

Might I add that each time HT sent a new module, we had to wait 3-4 business days for USPS which the truck sat each time. So I was beyond frustrated and the shop was soon to throw their hands up. My buddy stuck with it and tried a few things while we waited. IF all else failed, we were going to pull the bypass kit and replace the secondary air system.

Hewitt Tech Technician also said that if the truck was driven a while with the initial codes of P2445 (old owner did drive a while) it could mess up the pressure sensor or ECU. If the FORTH module did not work, i was going to have to change the pressure sensor out with the additional Hewitt Tech pressure sensor kit that does not come with the GenII 3V bypass kit.

End result was, we got a FRESH FOURTH Hewitt Tech module and my friend also narrowed down the cylinder misfire to a bad coil that was contributing to the rough idle. Once they installed the new module and replaced the bad cylinder coil they drove the truck a ton and still had a pending code (P1442). After a couple of days of driving the pending code never triggered and now i have no codes with no CEL.

Below is my code throws since I bought the truck.

P2445 - ordered and installed HT bypass kit

P1445 & P2441 & P1613- ordered and installed 2nd HT bypass module

P1440 or P1443 & P1613 intermittent with intermittent P0420 with rough idle- installed third module brought truck to shop.

P1440 or P1443 & P1613 intermittent with rough idle- installed Fourth module

P0302 & P2440 - changed coil

P1442 pending and then disappeared.

End result was I think I had a perfect storm. I had a bad batch of HT modules and then had a cracked coil after change of spark plugs. Bad module contributed to the codes and CEL and rough idle was due to the bad coil. Once all was replaced, we have driven the car for 3-4 weeks with no codes.

A note about Hewitt Tech. They were great the entire time and helped work through each series to try and help figure out what was going on. Having to go through 4 modules sucked but out of our control and I may have helped them find out they had a bad batch of modules. Regardless, they sent new modules each time with no questions asked (although USPS was terribly slow each time) and we narrowed it down.

I hope that solved it but man was it a wild goose chase of diagnostics. I hope this helps you. I also did NOT take off the intake and have NOT removed any SAIS component. Let me know if you have questions.

Best of luck!
 

jerryb

Supporting Vendor
Joined
Jul 30, 2016
Messages
2,266
Location
pensacola fl.
Good to hear.
When I ordered mine it said they were out of sticky, but magically should up in about a week. It was around the time or shortly after you got yours, I think. Ordered in Feb I think.

I do wonder about 2 p1613 codes in 30 days.
My calves are removed front and back, pump and pressure sensor are there, just unplugged.

Been great other than that.
Oo, no cat converters either.

Thank you for the info.
 

Users who are viewing this thread

Top Bottom