Engine Light

Thank you guys again I still haven’t pulled the trigger on this yet.

 

Shifty I live in Plaistow NH, if you know of a shop around here?

 

I've been to NH and VT once in my life to see what the two states were like, on my way traveling up to ME. Outside of that, and having a piece of art on my wall my wife bought from an artist known up that way, I got nada.

That's not to say the rebional forums on here, or someone else here near to the Mass border, maybe north/west of Haverhill or Merrimac may know?

 

Question? Are the upstream and down stream o2 sensors the same on each side? So if I get two of each, I should be good. Going with Gen 1 bypass, one because it sounds like the consensus is it does the job and two my mechanic said he won’t mess with the ECU and soldering. It’s illegal here so I need to pay him cash. He said he could get fined $10,000 doing it.


ththe job

 

Just ordered the Gen 1 from HTHewitt

 

It varies from year/model/drivetrain.

Look up your part number at www.densoautoparts.com

DO NOT order the part marked "Universal", you want the "Exact fit" (OEM) part. Then run that part number over to RockAuto.

If you need help finding the part, gimme your engine (v8/v6?) and cab type. I see you have a 2006 4WD, I just don't know if that's a V6 (which could be auto or manual) or if it's a V8. If I had your cab type, I could deduce it's a V8. I assume V8 but don't want to assume anything.

 

Yup I confirmed through Densos website those are the correct (direct fit) 02 sensors

$124 234-9051 Right-Bank Upstream with 4-Wire 8.5” Option Air Fuel Ratio Oxygen Sensor

234-9051 &

$47 234-4260 Oxygen Sensor

234-4260 that I listed about , ordering now, thanks again. This forum is invaluable

 

Please note that the HT Bypass Kit will not address the codes associated with the O2 sensors. I have included a link below included a chart that will details SAIS codes covered by our Products. If you have any question please do not hesitate to contact us.

Secondary Air Bypass Kit - Comparison Chart | Hewitt Technologies (hewitt-tech.com)

 

thank you, I am replacing both 02 sensors on both banks while I’m having it done. Once it’s completed I’ll post my cost to have it done.

 

Okay guys , had the Hewitt bypass kit installed Friday morning, mechanic did drive cycle test and all looked good, codes didn’t return, drove a day and a half, put about 120 miles on it yesterday all good, drove 20 minutes to church this morning and engine light came on just as i arrived. Went to autozone after church and it threw (2) P2445 codes and the C1241. He installed the plates with the kit where the manifold meets in the back of the engine because at the location it says to put them the first (top) bolt on each side broke off. I live in the rust belt so not surprised. But why would it throw these codes again?

 

Contact @HewittTech01, their support team can help you work through it. From what we've seen on here, it's not uncommon to toss those codes (at least the P2445, I can't recall on the C1241). They are very responsive and will know more than anyone on this forum will.

 

the problem is the truck is acting like it did prior to fixing, no power, if you floor it, it revs a little but doesn’t do anything.

 

The P2445 is pretty normal, and there's even a TSB for it. You may want to revisit the 1st page of this thread.

The C1241 is the most confusing for me. I dont' think you answered my question about it in reply #4 waaaaay back at the start:

Can you answer those questions, please?

And are you certain there's no corrosion in the wiring of your battery cables or corrosion on the terminal?

Can you stop by any major chain auto parts store and have them test your battery, it's free and only takes 15 minutes?

 

@shifty` As always thanks for the tag and we strive to be as responsive as possible. I also agree with you my initial through as we are in the dead of winter is the known "Cold Weather Glitch".

@NH06Tundra I believe you called in this morning and it was good speaking with you. As we discussed; we need to first rule this out before troubleshooting the module.

• 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,

 

So your saying If I clear the codes, it will run normal? and to avoid it happening again on any day colder than 32 degrees I should warm up the engine as usual but turn it off and restart it before driving and at that point if I go over 50 it shouldn’t trip!

This past Saturday it was about 13 degrees, I let the truck warm up about 10 minutes maybe 15 and drove an hour at times going over 50 and it never kicked the codes? Why didn’t it happen on that day rather than Sunday morning same warm up time?

 

I am running a diehard silver series battery and yes the alternator is the original.

I am warming my truck as I type this after removing the battery cables to clear the codes. I will turn it off after 6 or 7 minutes of warming up ( turning the key all the way off) then restart and drive it to see if it runs normal. The temperature is currently 35 degrees.

I never saw this truck going into limp mode issue before two months ago and it happened the first time when the weather was warmer and not even close to freezing about two months ago. So I’m thinking this doesn’t have anything to do with the known “glitch”.

 

So when I went out to my truck after warming it up I noticed that it was idling very low, I turned it off for about 10 or 15 seconds then restarted it and took it for a ride and drove normal again so it wasn’t in that limp mode. I got it up to 50 only for a couple of seconds because on these roads it’s just hard to get to 50, drove back to my house when I came to a stop to put it in reverse to park it stalled out I got it started but it’s idling extremely low and then the engine light came on I don’t know if it’s going to drive normal after the engine light came back on, I didn’t dare to take it out right now again in case it died and I couldn’t get it going again. It has been idling fine. This only happened when I unhooked the battery and hooked it back up….hmmmm

 

I've seen batteries 6 month old go bad, things just aren't made like they used to be. But I have an SPX OTC to test it with, similar to what the LAPS has. It takes almost zero effort to test with a proper tester (since simply checking voltage means little to nothing) to at least rule out the C1241, if there's an auto parts chain store anywhere near you.

How many miles on that alt? Mine caught fire at right around 65,666 miles, back in 2019. And I'm not kidding on that mileage, and the fact it caught fire. I found it pretty hilarious. I replaced with a new Denso, and that solved a few other issues I was having. Of course you can easily test that also if you have a DMM handy.

 

This is normal. Pulling the battery cable for as long as you have has forced the computer to reset and thus re-learn everything. Expect shit idle for the next 5-20 miles while it recalibrates itself, or let it sit idling for 20-30 while it figures things out.

Simply clearing the codes using a hand scanner will take you out of limp mode. I keep a bluetooth OBDII dongle in my truck at all times and use it to reset codes. Occasionally I go into limp mode due to a errant knock sensor reading. It's happened twice in 3 years, despite knowing 100% I don't and haven't personally had rodents under the intake manifold. Which reminds me, I need to throw my snake cam up under there to look for previous incidents with previous owners...

 

seems legit to me...

 

Actually my memory was fuzzy.

Alternator caught fire at 66566. I took a pic of the mileage.

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Got that replaced, then B2 O2 sensor took a shit at 66655. Took another pic. As you can see, I take pics of stupid shit.

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I took another pic at 66666, expecting something else stupid to happen, despite it only being 11mi later. Mind you, I'd only had the truck for 5k miles at this point, so was none too happy about all this crap popping up, was thinking I got a lemon. "But low mile trucks are better", so many people think...

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I was so close ... missed it by 9 miles.

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Tested battery/alternator this morning

Truck off volts read 12.7 12.2 12.76 etc.

Truck running no load 14.2 V

truck running with lights on and blower on 12.54 / 12.69

With lights, blower and radio on 12.52v

After turning it on putting it under load I turn the truck off and then I restarted the truck with no loads and it would not go above 12.77

should I be looking for a certain alternator? I called the auto parts place they said they have 80, 100 & 130 amp alternators? I have the tow package on my truck 285CI

 

I'd recommend to go Denso. If you haven't replaced your serpentine/drive belt within the last 50k-60k miles, you need to remove it to install the belt, so it may be worthwhile to replace.

For our '06 trucks, tow package came with the Denso 130a alt. Your OEM may actually have the sticker still on it indicating which model it is, but it doesn't matter, I'd go with the largest compatible one that came with our trucks (I say that knowing you can technically install the Sequoia 150a alt). If your truck has the OEM 7-pin trailer plug on the driver's side of the hitch receptacle, your truck should've had the 130a, which is here on RockAuto or here on Summit Racing.

Your truck should have two splash aprons in the passenger wheel well tamped "R" (in front of strut) and "RR" (behind strut). If you remove the forward-most one ("R") it will give you a clear line-of-sight to the alternator to detach and re-attach its wiring. Wheel removal isn't necessary, this was just a helpful tip I found. Skid plate needs to come off to drop the alt out. After removing the serp belt, and popping the alternator bolts out, one is shared with the power steering pump, you may find you need to loosen the PS pump and slide it forward some to get the alternator off that shared post.

Look, I'm not a "USE OEM ONLY!" guy on everything. But this is one of those jobs where it's 60-90 mins work you won't want to repeat again later. You're also dealing with an electrical component. General rule of thumb is, if it's an electrical component, use Denso brand. You should get just as much life out of it as the original from the factory. Aftermarket brands don't do the same level of testing, it's why they offer a lifetime warranty - they know you'll be back to cash in on that within 2-3 years, when your alternator is failing again due to poor QA/QC from the factory, but they don't pay for your labor.

If you have somewhere local to you that carries Denso, awesome. There are some stores that do. It'll make core easier.

I'm assuming the C1241 is probably related to your alternator giving up the ghost. That said ... your ECU/ECM could be attributed to both codes, frankly. ECU doesn't cost much to replace if you buy from a reputable source like Flagship One ("FS1"), but I'd aim for the alternator first. I'm not 100% positive if replacing the ECU with a newly-flashed unit would fix the bug with P2445. And on that note - several people have had their truck for many, many years and never popped the P2445, then suddenly started popping it left and right. I know it's frustrating.

 

Yes, that is the work around we have discovered that prevents the Glitch from tripping. Again, the P2445 will only happen under very specific circumstance and usually only after a cold start (the vehicle sitting for 7 hours or longer). Have you tripped the P2445 since installing? If so, are you sure it was an Active/Current code? It could have been a Stored/Historical code and the P1241 could have been causing the CEL to trip.