[thefatcat]

I have a weird issue with my 2016 4Runner Limited:

When going up a very slight incline at low speed I get a sputter / stutter in the engine or drive train (I cannot tell which). It occurs only when the engine is around 1100-1200 RPM and speed is anywhere between 15-30 MPH. It disappears as soon as I step on the gas a little more. It does not happen every time that I am on a slight incline but enough to where I am annoyed by it.

I just replaced the ignition coils and that did not do the trick like my mechanic and I thought. The spark plugs are maybe 2-3 years old. When I hook up my little handheld Motopower scanner it does not pick up any codes either.

Any thoughts on what the issue might be?

Thanks

[spartacus]

Originally Posted by thefatcat

I have a weird issue with my 2016 4Runner Limited:

When going up a very slight incline at low speed I get a sputter / stutter in the engine or drive train (I cannot tell which). It occurs only when the engine is around 1100-1200 RPM and speed is anywhere between 15-30 MPH. It disappears as soon as I step on the gas a little more. It does not happen every time that I am on a slight incline but enough to where I am annoyed by it.

I just replaced the ignition coils and that did not do the trick like my mechanic and I thought. The spark plugs are maybe 2-3 years old. When I hook up my little handheld Motopower scanner it does not pick up any codes either.

Any thoughts on what the issue might be?

Thanks

The mechanic do any other trouble shooting? Check the fuel trims when driving uphill. start out with simple stuff. Clean engine air filter, Clean maf, check the vacuum lines. Clean the throttle body. Run some top tier gas in it see if that helps. Throwing in some new oem sparkplugs won't hurt any thing. How many miles on the truck?

[CutthroatSlam]

Stop throwing parts at it, as you are simply guessing and that gets expensive.

If you can’t replicate it consistently and it’s not throwing codes, then I would drive on.

[djeepin]

D is for hwy cruising. go uphill, add some gas and trans kicks out of overDrive into s4 or depend of speed and load, may be s3. it fast, but noticeable. EDUCATE YOURSELF BEFORE OPERATING ANY MACHINERY the best way to save transmission is to shift to D and click left to s4, and stay this way, untill you hit hwy

[thefatcat]

Originally Posted by spartacus

The mechanic do any other trouble shooting? Check the fuel trims when driving uphill. start out with simple stuff. Clean engine air filter, Clean maf, check the vacuum lines. Clean the throttle body. Run some top tier gas in it see if that helps. Throwing in some new oem sparkplugs won't hurt any thing. How many miles on the truck?

No other troubleshooting performed. Dumb question..what is MAF? Vehicle just turned over 200K miles. No other issues other than this one.

[spartacus]

Originally Posted by thefatcat

No other troubleshooting performed. Dumb question..what is MAF? Vehicle just turned over 200K miles. No other issues other than this one.

The MAF sensor is on the intake tube downstream of the air box there are two screws holding it. Disconnect it and use a crc maf cleaner. It measures the air for the ecm. 200K is a good healthy milage to do this and replace the pcv valve if it's never been done before.

https://youtu.be/dk6CnOzIMOs?si=M0sBs6x6UW4u4oB7

[flyrv9]

MAF = Mass Airflow Sensor. They can get dirty and cleaning can help in cases like this.

[Jeremy556]

Start by putting your Toyota coils back. They almost never fail, aftermarket ones are garbage and will fail on you in the future.

As mentioned, using a good scan tool, drive and watch the A/F trims from the O2 sensors and misfire counters.

[Ezlife45]

Did you do a fuel pump recall? I did for my '14 LE and in a couple of years the "upgraded" pump was crap. Except i was throwing codes. When I brought it to a good shop, I was only making 3 PSI at my fuel pump. Maybe try to see if someone can to a fuel pressure check. No schrader valve on my fuel rail so you need someone with the right equipment.

[thefatcat]

Originally Posted by Ezlife45

Did you do a fuel pump recall? I did for my '14 LE and in a couple of years the "upgraded" pump was crap. Except i was throwing codes. When I brought it to a good shop, I was only making 3 PSI at my fuel pump. Maybe try to see if someone can to a fuel pressure check. No schrader valve on my fuel rail so you need someone with the right equipment.

No fuel pump recall for me.

[thefatcat]

Originally Posted by djeepin

D is for hwy cruising. go uphill, add some gas and trans kicks out of overDrive into s4 or depend of speed and load, may be s3. it fast, but noticeable. EDUCATE YOURSELF BEFORE OPERATING ANY MACHINERY the best way to save transmission is to shift to D and click left to s4, and stay this way, untill you hit hwy

Thanks for the input. I have noticed that if I am in s4 on side streets that the problem goes away. It only occurs when I am in D.

If it is a transmission issue....it should happen all of the time correct?

[thefatcat]

Could it be a torque converter?