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Hyundai i40 exhaust, emissions and leaks problems

DVSA MOT tests 2022–2025 · 13,789 MOT tests · Updated

At 9 years, 1.5 in 100 MOT tests of the Hyundai i40 failed on exhaust, emissions and leaks, against 2.4 for all class 4 vehicles the same age (all test years; 13,789 MOT tests) [1].

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  • Against all class 4 vehicles the same age: fails less often than all class 4 vehicles the same age (0.5–0.7×) (all test years), 207 MOT tests with a fail
  • By age: seen at 10 ages from 4 to 13 years, 85,833 MOT tests
  • Most common fail: Malfunction indicator lamp: inoperative or indicates a malfunction, 0.8 per 100 MOT tests

Figures are for the model as a whole, not for one car.

What the MOT tests show

What we know

1.5 fails per 100 MOT tests at 9 years, against 2.4 for all class 4 vehicles tested at 9 (all test years). The Hyundai i40 fails less often here.

Why it matters

An exhaust, emissions and leaks fail stops the car passing until it is fixed; the most common one is rated major by DVSA.

What to check

Start the car from cold and look for smoke at the exhaust, listen for blowing joints, and look under the engine and gearbox for fresh oil or fluid drips.

Hyundai i40 exhaust, emissions and leaks fails by age

Hyundai i40 exhaust, emissions and leaks fails per 100 MOT tests by ageSolid line: the Hyundai i40. Dashed line: all cars the same age. The table below lists every value.0244 years: 0.9 per 100 (all cars 0.7), 1,715 MOT tests45 years: 1.1 per 100 (all cars 1.0), 4,350 MOT tests56 years: 1.4 per 100 (all cars 1.3), 8,005 MOT tests67 years: 1.4 per 100 (all cars 1.7), 11,129 MOT tests78 years: 1.5 per 100 (all cars 2.1), 13,563 MOT tests89 years: 1.5 per 100 (all cars 2.4), 13,789 MOT tests910 years: 1.5 per 100 (all cars 2.8), 13,520 MOT tests1011 years: 1.5 per 100 (all cars 3.2), 10,158 MOT tests1112 years: 1.9 per 100 (all cars 3.7), 6,222 MOT tests1213 years: 2.5 per 100 (all cars 4.3), 3,382 MOT tests13
Fails per 100 MOT tests by age, all first-use years pooled. Hyundai i40 All class 4 vehicles the same age
AgeMOT testsFails per 100All class 4 vehicles the same age
41,7150.90.7
54,3501.11.0
68,0051.41.3
711,1291.41.7
813,5631.52.1
913,7891.52.4
1013,5201.52.8
1110,1581.53.2
126,2221.93.7
133,3822.54.3

All first-use years of the Hyundai i40 pooled at each age, against all class 4 vehicles at that age over all 2022–2025 test years.

What fails in the exhaust, emissions and leaks at 9 years

Fails

Advisories (not fails)

Diagnose engine warning light cost

Repair figures are estimates, not quotes: how we estimate repair costs.

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  • Model risks for this year and fuel
  • What similar cars did at their next MOT
  • Repairs ahead
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See a sample report

How to check on a test drive

Start the car from cold and look for smoke at the exhaust, listen for blowing joints, and look under the engine and gearbox for fresh oil or fluid drips.

The most common advisory here in MOT records: Engine oil leaks: leak, but not excessive.

Check one Hyundai i40, not the average

The figures here describe Hyundai i40 cars as a group. These free tools answer for one car. Each line says what the tool reads.

Other Hyundai i40 problems

Exhaust, emissions and leaks on rival models

Questions people ask

Does the Hyundai i40 have more exhaust, emissions and leaks problems than other cars?

0.5 to 0.7 times the exhaust, emissions and leaks fail rate of all class 4 vehicles the same age at 9 years (all test years), from 13,789 MOT tests. The interval is clear of 0.8 in the same direction at 4 of the 10 ages seen (ages up to 18 with at least 100 MOT tests with a fail).

How common are Hyundai i40 exhaust, emissions and leaks problems?

1.5 in 100 MOT tests at 9 years failed on exhaust, emissions and leaks, against 2.4 for all class 4 vehicles the same age (all test years; 13,789 MOT tests).

What is the most common Hyundai i40 exhaust, emissions and leaks fail?

0.8 in 100 MOT tests at 9 years: Malfunction indicator lamp: inoperative or indicates a malfunction (111 MOT tests with it).

Sources

  1. Driver and Vehicle Standards Agency, Anonymised MOT tests and results, 2022 to 2025. DVSA MOT data, Open Government Licence v3.0, 85,833 MOT tests. Accessed 7 Oct 2026.
  2. Office for National Statistics, Consumer price inflation, local price quotes (car repair items). ONS price quotes, series 610236. Accessed 7 Oct 2026.

Parts: against all class 4 vehicles at the same age, all 2022–2025 test years pooled, not adjusted for mileage. Breakdowns and non-MOT faults are not in this data. How we compare