Hi Everyone

I'm experience rough engine run when coming to a stop at the lights or while stopped at a light transmission in D, it happened 3 - 4 times over the last 3 months. Idles just fine in P.

It's a 2015 trail edition, with around 180k miles and the last 50k with Magnuson SC installed. Been running great with lots of pull, no issues, maintenance upto date, engine air filter replaced 3000 miles before, NGK spark plugs have 10K miles on them. Oil change every 3500 miles. Fuel is 98 Ron (93).

Scanned for codes there are U0100, U0101 lost communication with Traction Control Module. No misfire codes.

Did anyone experience similar issues? What did you do to resolve them?

Thanks

I would recommend cleaning your mass air flow sensor. Just do it correctly.

Be sure to always use Top Tier gas as recommended by Toyota. Top Tier gas has more cleaners in it than other gas, so your fuel injectors and mass air flow sensor stays cleaner.

If after you clean the mass air flow sensor, as others have suggested, you are still running rough, put a bottle of Techron in the gas. Techron is essentially adding more Top Tier gas cleaners, which will help your fuel injectors stay clean.

With those miles, I would also suggest cleaning the throttle body and plate, both sides.

I second cleaning the throttle body:

Should you clean your Throttle Body and How to clean it on Toyotas - YouTube

my 4th gen 4R with the 4.0 started doing this around 175k miles, just a weird stumble every now and again when i cranked it. Then maybe around 195k miles it turned into a stumble here and there at a red light or taking off from a stop sign ect. I noticed it getting a little more frequent, like instead of once a month, it started doing it once a week. Somewhere around 210k miles i was driving down the interstate at speed and it felt like someone shot a 50cal rifle thru my engine, a loud "wooPoww" like a backfire followed by instant loss of power and a fluttering engine. The engine felt like it dropped to a 3 or 4cyl, the fluttering noise was awful and i barely had enough power to maintain 65mph to get back home.

Turns out it was 1 coil pack. Drivers side rear, closest to the firewall. After talking to a few mechanics, they all claim thats the cylinder that eats the spark plugs up the fastest and when the plugs start going down it forces the coil to work harder and burns the coils up.

Not sure if you can test a coil or not, but that would be my guess from your description.

So based on a previous post, I go with my personal favorite, check plugs first.
I had a truck that ran fine most of the time, but would idle rough and stall on days below 40. I forgot when I last changed plugs. I finally wound up changing plugs and wouldn't you know it, runs like a top. Gaps were 10 to 20 oversize. From wear, not from incorrect gap.

Thanks everyone for your suggestions they are all valid and probable cause of the issue. Just to give you an update, last weekend I put in a new MAF (US$100), got a throttle body cleaner and an OEM TB gasket. Removed the the TB, cleaned it up quite nicely (it wasn't that bad). But when I tried to put it back the new gasket did not fit because the SC uses a different one that I had to reuse. I don't know where to look for it online.

So far she runs fine and idles better than before, had to disconnect the battery to reset plate position sensor.

Now I need to find gasket, guess I'll email Magnusson. Also, the TB sensor connector is quite brittle from the engine heat and broke, zip tied it for the time being and have a new one on order.

Regards