Model Reports 4 min read Updated 18 Oct 2026

Toyota GR Yaris 2021: reliability & common MOT faults

In 2025, 92 in every 100 first MOTs on a 2021 Toyota GR Yaris were passes. Most common reason for a fail: Tyre condition (front).

Summary

The 2021 Toyota GR Yaris follows the pattern of the model years either side.

At a glance

How 2,863 first tests went in 2025.

Passed first time
92 in every 100
Did not pass first time
8 in every 100217 failed first-attempt tests
The typical car
4 yearsabout 16,716 miles
First tests counted
2,863

What failed most often

  1. Tyre condition (front)38 in every 100 failed tests

How we count this. Data: UK MOT open data, 2025. Only Class 4 cars on their first MOT of the year are counted. A car that fails and is fixed at the test station still counts as a fail in the first-attempt rate. These are raw results, not adjusted for age, mileage, or peer mix. The MOT does not test engine or gearbox internals.

Note:

These are patterns across 2021 Toyota GR Yaris vehicles in 2025, not a prediction that any one car will have them. Faults are grouped by part of the car. A wear pattern follows age and use more than the way the car was built. They come from MOT defect codes, not manufacturer bulletins, recalls or a diagnosis of any one car.

Noise, emissions and leaks

One fault: petrol emissions (with catalyst), 36 times as often as on similar cars.

Figures below are measured across the 217 failed first attempts in 2025 that had a mileage recorded, which allows a like-for-like comparison.

We only list faults with at least 20 failures and a rate of about 2.0 times that of similar cars, which keeps one-off results out of the list.

Petrol emissions (with catalyst)

Failed on 39 first tests36 times as often as similar carsLikely evidence

What it means

Emissions levels over the manufacturer's specified limits are Major, as are levels over default limits, which apply when no exact match is found for the vehicle. Dense blue or clearly visible black smoke at idle, held for a set period, is Major, except for certain older vehicles and two stroke engines where smoke is unavoidable. An induction or exhaust leak that could affect emissions levels is Major too.

Data: UK MOT open data, 2025. Compared with cars of the same age and mileage.

Tyres

One wear pattern: tyre condition (front), 2.0 times as often as on similar cars.

Tyre condition (front)

Failed on 82 first tests2.0 times as often as similar carsWear pattern

What it means

Exposed or damaged ply or cords are graded Dangerous. A cut in excess of the requirements and deep enough to reach the ply or cords is Major, and testers may open the cut with a blunt instrument to check its depth. A tyre contacting the vehicle through flexing or suspension movement is not a defect; fouling fails only at the time of test.

Data: UK MOT open data, 2025. Compared with cars of the same age and mileage.

Advisories

Other things testers noted as worn or close to failing, more often than on similar cars.

An advisory is a note from the tester about something that has not failed yet. It is an early warning, not a fail.

Tyre tread depth (rear)

Noted on 28 first tests2.7 times as often as similar carsWear pattern

Data: UK MOT open data, 2025. Counts cover advisories recorded on failed first tests only, compared with cars of the same age and mileage.

MOT pass rates

How first tests ended, and how the pass rates are counted.

Passed first time
92in every 100
Passed on the first test.
Fixed at the station
1in every 100
Failed, then fixed at the test station the same day.
Failed
7in every 100
Did not pass, and were not fixed at the test station.

First-attempt pass 92.4% of 2,863 first tests (2025): only cars that passed first time count. Official-style pass 93.4%: cars fixed at the test station also count as a pass. The 1 fixed and the 7 not fixed make the 8 in every 100 that did not pass first time.

Same model, other years

Passed first time in every 100, all tested in 2025.

YearPassed first timeFirst tests
2021 This car92 in every 1002,863
202292 in every 1001,381

Newer cars are younger, so look for a jump rather than the climb. A year earlier (2024), when these cars were a year younger, 93 in every 100 passed first time.

If you are buying one

What this year's MOT record means for the decision in front of you.

Mileage makes a modest difference on a 2021 GR Yaris.

Of 2021 GR Yaris vehicles with under 9,000 miles, 97 in every 100 passed their 2025 MOT first time. With 27,000 miles or more, 92 in every 100 did.

Under 9,000600 tests
97
9,000–14,000537 tests
96
14,000–19,000 Typical car545 tests
90
19,000–27,000621 tests
87
27,000 and over560 tests
92

What to check at your mileage

How often each fault turned up on a failed first test, by the car's mileage. Read it as: what is likely to need looking at on a car like the one in front of you.

Under 9,00014,000–19,00027,000 and over
Tyre condition (front)0.35.72.1

Faults per 100 first tests, by the car's mileage at the test.

Every figure here is a first-attempt MOT rate from DVSA open data for this model line, for cars of this model year tested in 2025. Each mileage band holds a fifth of the tests. MOTs do not test engine or gearbox internals, so this is a pre-purchase checklist, not a full reliability score.

FAQs

Short answers about how to read this model-year guide.

The 2021 Toyota GR Yaris follows the pattern of the model years either side. In 2025, 92.4% of 2,863 first MOTs on the 2021 Toyota GR Yaris passed first time (PRS: items fixed at the station the same day, counted as a fail). The official-style rate including PRS is 93.4%. Among 217 failed first-attempt MOT tests (test year 2025), Petrol emissions (with catalyst) appears more often than on similar cars (18.0% of those tests; 39 observed failures; about 36× more often than similar cars). There is no single reliability score here; this is a pre-purchase checklist built from DVSA open data, not a guarantee for any individual car.
Ranked by how often they were actually recorded, the items that most often failed a 2021 Toyota GR Yaris at the first attempt were Tyre condition (front) (37.8%), each as a share of the year's failed first attempts. That is what goes wrong most often on the car. The common faults table shows a different measure: faults that are unusual compared with similar cars.
Among failed first-attempt tests we highlight patterns that appear more often than on similar cars. Top example: Petrol emissions (with catalyst) (18.0% of those tests; 39 observed failures; about 36× more often than similar cars). These are statistical signals, not a diagnosis of any individual car.
Petrol emissions (with catalyst) shows up more often than on similar cars (18.0% of those tests; 39 observed failures; about 36× more often than similar cars). That does not prove a design fault. Age, mileage, and how the car was used still matter. Treat it as a pre-purchase checkpoint, not a manufacturer service bulletin.
Common MOT problem areas for the 2021 Toyota GR Yaris include Petrol emissions (with catalyst). These are the faults that stand out compared with similar cars, not a complete list of what can go wrong on any individual car.
Advisories flag issues noted at the test and are not a fail rate. We show advisory patterns that appear more often than on similar cars among failed first-attempt tests, separate from common failure rows. Use them as early-warning checks, not as a pass/fail score.
This page highlights MOT failure patterns for the 2021 Toyota GR Yaris (registration year) using UK DVSA open data for the selected test year. Patterns are compared with cars of a similar age and mileage. It is a buyer checklist from MOT defect statistics, not a full service history or manufacturer service-bulletin list.
No. MOT tests do not cover engine internals, gearboxes, or many electronic modules. Patterns here come from MOT defect statistics only and should not be read as engine or gearbox reliability scores.

About this data

How this page is built and what it can (and can't) say.

These figures come from UK MOT open data for this model year. We surface common failure patterns against similar cars, not a full reliability score, and not a pass/fail verdict on any individual vehicle.

2024 2025

What we include

UK Class 4 cars only. Normal MOT tests (not retests); first test per vehicle per calendar year; results pass, PRS, or fail.

Same-day repairs

PRS means the car failed items that were fixed at the test station and then passed the same day. We count PRS as a first-attempt fail in headline rates so same-day repairs do not hide problems.

How we compare

We compare this model year with other Class 4 cars of similar age and mileage in the same test year. This model family is left out of the peer group so the car is not measured against itself.

What this does not cover

  • MOTs do not cover engine internals, gearboxes, or many electronics; this is not a full reliability score.
  • Common faults come from MOT defect stats, not manufacturer TSBs or recalls.
  • Age and mileage matching reduces, but does not remove, differences in how cars were used and maintained.
  • If the data for a car is too thin to say anything useful, we say so rather than guess.

Contains public sector information licensed under the Open Government Licence v3.0.

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