Need Help Programming My Tacoma ECU — Stalls After 20 Minutes

Truck’s Been Down for Over a Month — Need a Tuner’s Brainpower
I’m in Chattaroy, Washington and I’m stuck on a problem with my 2017 Toyota Tacoma TRD Sport 3.5L V6 that I cannot solve on my own. I’ve tried just about everything I can think of — and I’m willing to pay for someone who can help me get this programmed and running right again.

Here’s the situation:

Stock VF Tuner file will not get the truck to run at all — it cranks but never fires and stays running.

The current tune I have on it will get the truck running for about 20 minutes, then it stalls and dies every time.

From what I can tell, it’s going into closed-loop fueling after warmup and something in that transition isn’t right.


This isn’t just about tweaking a few maps — it needs full programming so it will run and stay running without stalling.

Current Modifications:

Rough Country Cold Air Intake (Part #10547)

JET Performance Powr-Flo MAF Sensor (2015–2020 Toyota 3.5L)

RIPP High Performance Coil Pack System (for 3.5L V6 2GR-FKS)

aFe Power Silver Bullet Throttle Body Spacer Kit (Part #

$137 46-38010 aFe Power Silver Bullet Throttle Body Spacer Kit Toyota Tacoma 16-23 V6-3.5L #46-38010

46-38010)

$290 MBRP S5338P 3" Cat Back, Single Side Exit for Toyota Tacoma, Aluminum

MBRP S5338P 3" Cat-Back Single Side Exit Exhaust (Aluminum)

LT265/70R17 Cooper Discoverer AT3 LT tires (M+S rated)

2" Hub-Centric Wheel Spacers (6x139.7mm, 106.1mm center bore, M12x1.5 studs)

Running 92 octane


What I’ve Tried So Far:

Multiple VF Tuner tunes, including my own custom files

Full Mass Airflow Delete (MAF-off) configurations

Adjusting idle targets, startup fueling, and ignition timing

Recovery tunes with modified airflow and torque tables

Open-loop idle setups to prevent stalling after warmup

Fuel trim and cylinder fuel multiplier adjustments

Verified hardware: MAF sensor, coil packs, intake system

Immobilizer resets via Techstream and manual (paperclip) method


Datalog Symptom Details:

Truck idles fine after cold start and during warmup

As coolant temperature approaches ~180–185°F, AFR readings lean out noticeably right before stall

RPMs begin to drop in steps (small dips) as if airflow is insufficient, followed by a sharp fall

Once in closed-loop, short-term fuel trims swing heavily, long-term trims begin adapting right before stall

Stall occurs regardless of load or gear position — even at idle in park


If anyone here has the experience to help me program this ECU correctly — or knows someone who can — I’d be more than happy to pay for your time.

Thanks in advance,
Ben Thompson

 

Get rid of the RIPP coils, aftermarket intake and MAF sensor. That will solve your issues.

 

Yes, they have some questionable aftermarket parts installed. What was the last thing you modified before you encounter issues?

 

Everything worked perfectly with my mods until I used VF Tuner and it cleared the ECU’s learned memory. After that, everything went downhill.

I don’t see why I’d need to revert to stock hardware just to make the truck run — it already ran fine with my current setup before VF Tuner wiped those learned values. That tells me the issue isn’t the hardware, it’s the calibration.

My plan isn’t to go backwards — it’s to calibrate my current mods so they work even better than they did before, without having to remove them just to re-teach the ECU. VF Tuner caused the reset, so I just need to reprogram the tune for my setup.


If I have to I will put back in my original coil packs but I dont have the original MAF anymore, I have a Delphi MAF just in case.

 

I’d put $10 that your aftermarket MAF is the entire problem. It’s not reading correctly, causing the ECU to go into closed loop and it dies out as it’s not getting the info it needs to make it run.

The MAF is the most important sensor for the ECU to control fueling. Put an OEM (in a Toyota box, not from a parts store) MAF in and I bet your truck runs again.

 

Right now I’m running the JET MAF sensor with my cold air intake. I do still have my original coil packs and a Delphi MAF I could swap in, but when I tried the Delphi with the stock tune it still wouldn’t run.

Since I no longer have the factory intake, that part’s staying. If you think swapping in the Delphi and the OEM coil packs would definitely help, I’ll do it — but if it’s just a guess, then my best option is to keep programming for the setup I have now.

 

I've seen those coils shut entire banks down. I always start with removing coils like that now.

 

I agree.

RIPP coils are JUNK. - Stay away from them.

 

You need an OEM MAF, and the aftermarket coils are certified garbage. A quick Google search or ChatGPT for the new kids will tell you that. Delphi doesn’t make Toyota MAF’s, at a minimum you need a Denso MAF, but even those are known to not work as well as OEM Toyota MAF’s (made by Denso).

You bought every snake oil mod known to man. Take them all off. The RC intake is one of the worst “hot air” intakes ever made, the spacer does nothing. If you want performance, it’s honestly really hard to beat OEM.

 

.Why did my truck run perfectly with these mods until VF Tuner touched it?
Before I ever used VF Tuner, my truck ran flawlessly with the JET MAF, RIPP coil packs, and cold air intake — no hiccups, no issues, no warning signs. I installed all of these within about a month of each other, and I could have installed them all in a single day and it still would have run just fine. In fact, it ran perfectly for well over a year without a single problem.

People often say you “have to tune” a vehicle when adding mods. In reality, tuning is about optimization — squeezing out maximum performance — not simply making the truck able to run. My truck didn’t need a tune to run properly with these parts; it was already running exactly as it should.

The problems only began the day I used VF Tuner. It cleared my ECU’s learned memory and replaced it with a baseline that wasn’t calibrated for my aftermarket parts. If the software is designed to tune and program a vehicle, it should be able to work with common performance mods and calibrate them for best performance — not force owners to revert to stock equipment they may no longer have.

From my perspective, the software should enhance compatibility with aftermarket upgrades, not erase the learned data that allowed them to work flawlessly in the first place. I understand everyone’s opinions, but it still makes no sense why the truck now won’t run longer than 20 minutes when it was perfect before.

I completely disagree with the idea that my coil packs, MAF, or other parts are “garbage” or “snake oil.” Sure, some companies exaggerate numbers — maybe a “40% more airflow” claim is really 10% — but reputable manufacturers don’t go through the expense of designing, testing, and selling these products without data to back them up. That data might not be in the ad copy, but it exists.

Even if some mods like throttle body spacers or cold air intakes are debated, they still have effects — a CAI can improve airflow and sound, a spacer can subtly change throttle response and tone, and together with a good exhaust, they contribute to better combustion and performance. It’s all about the system working together.

And this is the key: my truck ran flawlessly with these mods for over a year. The only time it stopped running correctly was after VF Tuner wiped the learned ECU memory. That’s not a parts problem — that’s a calibration problem. With proper programming, these parts can work in harmony, and I’m confident that once we have the tune dialed in, this setup will prove the critics wrong.

Each to their own — but I know what my truck was capable of before, and I know we can get it back there with the right calibration.

 

Learned values do not get reset by reflashed calibration. You have to use Techstream to do that.

 

Good luck to you. There is no way to scale/correct the MAF error in VF for the 3rd Gen Tacoma. So there isn’t a way to “calibrate” for your sacred Jet MAF. The RC intake is also inducing error you can’t correct with current tuning maps in VF.

Search this site for RIPP coil pack failures. Very common.

 

What is MAF numbers under Idle in the Datalog (gm/sec)?

 

“At idle (600–900 RPM), my MAF averages about 4.0–4.3 g/s across multiple datalogs, with a range of roughly 2.2 to 16 g/s. I checked two separate runs and the readings are very consistent, so the sensor seems stable.”

 

Here’s my most recent datalog (“Let’s GOOOO!!!”)

ECU: 89663-04B04

Tune: YW Version 2 (untouched)

MAF: JET Performance Powr-Flo

Mods: Rough Country CAI, RIPP coil packs, aFe throttle body spacer, 3” MBRP cat-back

Fuel: 92 octane

Run time: ~19 minutes before stall during warmup transition

Goal: Find out why it stalls once warm despite running great cold

 

Please listen to the people here. I understand the fantasy of the performance pot of gold at the end of the rainbow, but short of a turbo or supercharger you’re not going to find it with bolt ons, higher octanes, tunes, etc. PLENTY of people here have tried that route and made miniscule gains at best. Most will only make the truck louder, or in the case of a tune more reactive. They will not give you any detectable HP gains if that’s what you want, and most will cause damage to the engine over time, looking at the cold air intake and RIPP coils specifically.

So to fix this let’s start with the fact that you’ve seriously modified the trucks entire intake and ignition system with in most cases parts that are worse then OEM, while also running a higher fuel octane AND added a tune. I know this sucks to hear since you sunk a lot of time and money into this, but if you want a solution well, here it is.
Start the unf*cking process there, get rid of all of it and go back to stock. If you really want to chance the performance fairy, add things in one piece at a time.

 

If you have Techstream or other capable of logging misfires, get that data also.

it’s your MAF, or RIPP coils, or the RC intake, or all of the above. But I’d start with getting an OEM MAF if you’re not logging misfires which would point to the coils.

 

I looked it it.
I agree with others that you MAF not metering correctly.
Normal idle 2.5-3.5. Yours is all over the place.
It shows 3.9 at 750 RPMs and then 5.45 at 655.
Long fuel trims at 40%. Short fuel trims are getting over 15% Toyota normal is -15% to 15%
Also check your absolute load. It is MAF dependent.

I would get oem intake, load stoke tune file and get it running before you cook it

 

I think my point keeps getting misunderstood, so let me set the record straight.

I’m not chasing horsepower anymore. Yes, I was originally trying to tune for more performance, but that’s not what this is about anymore.

Here’s the reality:

My truck ran perfectly fine with my setup — JET MAF, RIPP coils, Rough Country CAI, throttle body spacer, exhaust, etc.

No misfires, no codes, no drivability issues. It worked great.

The problems only started after I used VF Tuner.


The second I flashed with VF Tuner, the ECU lost all of its long-term learned memory (fuel trims, idle adaptations, etc.). People keep saying “you need Techstream to wipe learned memory” — that’s not true. VF Tuner does it every time you flash a file, stock or modified. That’s why the truck instantly stopped running the way it had before.

And this is why simply putting the stock tune back in didn’t fix it. It’s not the same stock behavior anymore — because the adaptive data that let the ECU run my setup before is now gone. I basically went from “stock tune + learned adaptations” to “raw stock tune with zero learning,” and that’s why it won’t run the same.

Now, look — I get why some of you don’t like my parts. Cheap intake, JET MAF, RIPP coils, whatever. That’s fine. But here’s the reality: they all did their jobs, and the truck already proved it could run flawlessly with them. A coil pack makes spark, a MAF reads airflow, an intake feeds air. They worked then, and they should work now.

Yes — one or more of you said the MAF probably isn’t reading correctly anymore, and you’re right in a sense. But it’s not that the JET MAF is broken. It’s that the ECU lost the memory it used to have that allowed it to interpret the JET MAF correctly. Same goes for the coils, intake, and spacer — they all did their jobs and the truck already proved it could run with them.

The difference is: before VF Tuner, the ECU had adapted itself around those parts. It never needed me to “calibrate” anything — it just learned and ran fine on its own. After VF Tuner wiped that memory, it lost that adaptation. So now the truck doesn’t know how to live with the parts it was already running fine with before.

That’s the piece I’m trying to solve. None of my parts are “the issue.” The issue is:
How do I restore the ECU’s ability to adapt and relearn those parts again, just like it did before VF Tuner erased everything?

If the answer is “install OEM MAF, let it relearn, then swap the JET MAF back in,” fine. I’ll do that. But the key point is: this isn’t about chasing horsepower anymore. It’s about getting the truck back to its original working state with the exact same mods it already proved it could handle.

 

Whi h tune did you run with this setup?
Learning values do not determine the performance. Also, ecu does not use learning values until specific temp of the coolant.
Based on your data log you have a gross intake leak somewhere. One of your banks register AFR 18 (1.23 Lambda). ECU is constantly adding the fuel to compensate it. Thus your fuel trims are pegged at the max
I've been using quite a few tunes, but all if them follow Stoke closed loop. You should be in closed loop in 30-60 sec after the engine fires up.
Get back to stock configurations.verufy you dont have a hole somewhere and start again.
Also, get a proper scanner that supports Toyota. Vftuner is not designed for a deep diagnostics