GR Yaris GR Yaris power dips at low boost

Tim Ali

Tim Ali

New member
Joined
Dec 8, 2025
Messages
10
Reaction score
5
Location
Melbourne, Australia
Hi all, 4-year GR Yaris owner and first time posting

I just did my first track day the Yaris. Boy it was awesome.
The day after it’s now doing this weird power dipping between 4000-5000 rpm, right at that initial boost point. It’s like it stops accelerating for a second and farts from the exhaust.. or something cutting the acceleration out?

There’s no signs of anything else being wrong. No warnings on the dash.. Could it be an ECU thing??

I’ll be taking it to a dealer in the coming days, but wondering if anyone has experienced the same thing..

I drove it pretty hard all day, but it was always warmed up before every session. It’s been regularly serviced, recently 5 months ago, and this is the first time I’ve really push it this hard.

It’s a 2020 1st gen, completely stock and done around 25,000kms

Appreciate any thoughts
Tim
 
Does it do it on a full tank?
 
I had an issue with low boost which pointed to a faulty boost sensor (which are known to fail). No fault codes or lights displayed.

After reading advice on this forum I reset the ecu (pull negative lead off the battery for 15 minutes). Upon reconnecting the lead the car drove perfectly. Worth a shot before you pay for parts/advice.
 
Altocumulus said:
I had an issue with low boost which pointed to a faulty boost sensor (which are known to fail). No fault codes or lights displayed.

After reading advice on this forum I reset the ecu (pull negative lead off the battery for 15 minutes). Upon reconnecting the lead the car drove perfectly. Worth a shot before you pay for parts/advice.
Click to expand...
That’s really interesting.. thank you.
I have the car booked at a dealer now, but will definitely post what the outcome is
 
tamasd8 said:
Is it sorted out? What was it?
Click to expand...
Nope not sorted yet.. I’m in a bit of a pickle atm.

So, I took it to a dealer, took a tech for a drive who recognised something’s not right.

I Ieave the car with them, they tell it’s ready to pick up.. great!
When I get there the tech has gone home for the day as has my “representative”. So can’t debrief with anyone who worked on the car.

The hand over person just read out what they did on the major service.. then said “in terms of your problem, the tech said he was happy after the service and couldn’t replicate the problem. But if it keeps happening to come back”

I wasn’t happy with the customer service at all and made a slight fuss, but then accepted it, got in the car and drove away. And guess what, replicated the problem STRAIGHT AWAY.

Called and complained to my representative the next morning. She was actually very good and said she’d have the Head tech call me.. they still haven’t called 3 days later.

I’m now thinking of just going to a tuner shop and ditching the dealer experience.. Do I even bother continuing to try with a dealer?? Am I barking up the wrong tree trying to get an enthusiast experience?

Sorry for the long story, once this is sorted I’ll be making a YT vid for my channel, because I think it’s a story worth telling
 
Not just Toyota GB then that are awful, unsure if that's a relieving feeling or not.

I'd ask them to replace the boost sensor if it's still under warranty, if it isn't, certainly over here, the specialists are much better than dealers anyway.
 
Tbh. I'm expecting the same from Toyota in my country, I am already considering to go to a 3rd party service with these issues, and just keep the general maintenance with Toyota because of the warranty.
 
jash19 said:
Not just Toyota GB then that are awful, unsure if that's a relieving feeling or not.

I'd ask them to replace the boost sensor if it's still under warranty, if it isn't, certainly over here, the specialists are much better than dealers anyway.
Click to expand...
Wow ok, that does make me feel better thank you.

Conveniently it’s just fallen out of warranty last month.. I’m researching specialist now, so probably go down that road. Feel like I’ll be wasting energy trying to fight with a dealer.

Thanks man, I’ll keep you posted
 
tamasd8 said:
Tbh. I'm expecting the same from Toyota in my country, I am already considering to go to a 3rd party service with these issues, and just keep the general maintenance with Toyota because of the warranty.
Click to expand...
Yep I’ve stayed true to Toyota through the warranty period, 6 services over 2 dealerships. Honestly when nothing’s going wrong they’ve been fine, and affordable (I find)
 
Tim Ali said:
Hi all, 4-year GR Yaris owner and first time posting

I just did my first track day the Yaris. Boy it was awesome.
The day after it’s now doing this weird power dipping between 4000-5000 rpm, right at that initial boost point. It’s like it stops accelerating for a second and farts from the exhaust.. or something cutting the acceleration out?

There’s no signs of anything else being wrong. No warnings on the dash.. Could it be an ECU thing??

I’ll be taking it to a dealer in the coming days, but wondering if anyone has experienced the same thing..

I drove it pretty hard all day, but it was always warmed up before every session. It’s been regularly serviced, recently 5 months ago, and this is the first time I’ve really push it this hard.

It’s a 2020 1st gen, completely stock and done around 25,000kms

Appreciate any thoughts
Tim
Click to expand...
Hi all! I finally have an answer to what this issue is.. it’s taken ages, lots of investigation and diagnosis but it’s now getting fixed BY TOYOTA

It’s the HIGH PRESSURE FUEL PUMP

I’ve made a reel to explain and I hope it helps someone too. 😊

 
You must log in or register to reply here.
Back
Top