2004 Porsche 911 (first used 2004) MOT pass rate, common failures & what to check
In 2025, 84.5% of Porsche 911s first used in 2004 passed their MOT first time, against 57.8% for all cars first used in 2004. Across 7,286 911 first tests from 2023 to 2025, the most common failure areas were lamps and electrical equipment, noise, emissions and leaks and brakes.
This page analyses first MOT tests for Porsche 911s first used in 2004 (all trims grouped): 2021 to 2025 for the pass-rate trend, and 2023 to 2025 for the failure and advisory analysis — plus what is worth checking before you buy one.
Data: DVSA anonymised MOT tests to December 2025 · Calculated by SortedCars · Updated October 2026
How the 2004 Porsche 911 MOT pass rate has changed
Share of first tests passed in each year, 911s first used in 2004 against all cars first used in 2004 (any make or fuel; not adjusted for mileage, fuel or use). In 2025 the 911 figure was 26.7 points higher.
View this chart as a table
| Test year | 2004 911 | All cars first used 2004 | 911 first tests |
|---|---|---|---|
| 2021 | 82.3% | 53.9% | 2,581 |
| 2022 | 82.9% | 55.2% | 2,475 |
| 2023 | 82.8% | 56.0% | 2,451 |
| 2024 | 83.1% | 56.4% | 2,397 |
| 2025 | 84.5% | 57.8% | 2,438 |
Common 2004 Porsche 911 MOT failures
Share of the 1,206 failed first tests (2023–2025) with at least one failure in each area. A test can fail in more than one area, so the shares add up to more than 100%.
Most common failure items
| DVSA failure item | Share of failed first tests | Tests |
|---|---|---|
| Catalyst emissions: Lambda reading after 2nd fast idle outside specified limits | 14.8% | 178 |
| Position lamp: not working | 11.4% | 137 |
| Rigid brake pipes: excessively corroded | 9.5% | 114 |
| Drive shaft joints: constant velocity boot split or insecure, no longer prevents the ingress of dirt | 8.4% | 101 |
| Headlamp aim: too high | 8.0% | 97 |
Item names are DVSA’s own wording. 2023–2025 combined.
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What to check on a 2004 Porsche 911 before buying
The three areas where failed first tests most often had a fault, 2023–2025.
- Lamps and electrics. Ask someone to watch while you work the brake lights, indicators, sidelights, dipped and main beam, and the number-plate lamps.
- Engine and emissions. Worth checking that the engine warning light goes out after starting, looking for oil leaks under the car, and noticing any smoke from the exhaust.
- Brakes. Worth looking at the discs and pads through the wheel spokes for scoring and a worn lip, and noticing on the test drive whether the car pulls to one side or the pedal feels long.
Common 2004 Porsche 911 MOT advisories
Advisories are points the tester noted that did not fail the car. Most common on 2004 911s, as a share of all 7,286 first tests, 2023–2025.
| DVSA advisory item | Share of first tests | Tests |
|---|---|---|
| Rigid brake pipes: corroded, covered in grease or other material | 11.8% | 858 |
| Brake discs: worn, pitted or scored, but not seriously weakened | 8.1% | 588 |
| Tread depth: worn close to legal limit/worn on edge | 7.9% | 573 |
| Engine oil leaks: leak, but not excessive | 4.4% | 319 |
| Tyre condition: slightly damaged/cracking or perishing | 4.2% | 309 |
Questions about the 2004 Porsche 911 MOT
What is the MOT pass rate of a 2004 Porsche 911?
In 2025, 84.5% of 911s first used in 2004 passed their MOT first time, against 57.8% for all cars first used in 2004. A car fixed during the test counts as a fail.
What does a 2004 911 most often fail its MOT on?
Lamps and electrical equipment (in 40.1% of failed first tests, 2023–2025), noise, emissions and leaks (21.7%) and brakes (20.4%). The single most common item was “Catalyst emissions: Lambda reading after 2nd fast idle outside specified limits” (14.8%).
How often does a 2004 Porsche 911 fail its MOT?
In 2025, 15.5% of first tests on 911s first used in 2004 did not pass first time: 13.0% failed, and a further 2.5% had a fault fixed during the test (counted as a fail here). Across 2023–2025, 1,206 of 7,286 first tests did not pass first time.
What are the most common 2004 Porsche 911 MOT advisories?
“Rigid brake pipes: corroded, covered in grease or other material” (on 11.8% of first tests, 2023–2025), “Brake discs: worn, pitted or scored, but not seriously weakened” (8.1%), “Tread depth: worn close to legal limit/worn on edge” (7.9%), “Engine oil leaks: leak, but not excessive” (4.4%) and “Tyre condition: slightly damaged/cracking or perishing” (4.2%).
Is a 2004 Porsche 911 reliable?
An MOT pass rate shows what failed at the test, not how reliable a car is. For this group of cars the first-time pass rate went from 82.3% in 2021 to 84.5% in 2025. For one particular car, its own MOT history matters more than the average.
Other cars first used in 2004
The most-tested cars from the same year. Each page uses the same method.
2004 Ford Fiesta MOT statistics · 2004 MINI Hatch MOT statistics · 2004 Ford Focus MOT statistics · 2004 Toyota Yaris MOT statistics · 2004 Volkswagen Polo MOT statistics
Checking a specific 2004 911?
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