Used car guide

2004 Porsche Boxster: common problems and MOT failures

What MOT testers find on the Porsche Boxster first registered in 2004: we looked at the 6,148 MOTs these cars had during 2023–2025. Plus known faults and what to look at before you buy one.

6,148MOTs of 2004 cars, done in 2023–2025
75%pass first time (all 2004 cars: 57%)
3,800typical miles a year
2.8×the usual rate for exhaust emissions (catalyst)

What goes wrong more than usual on a 2004 Porsche Boxster?

Parts flagged at MOT more often on the 2004 Porsche Boxster than on all cars registered in 2004.

  • Exhaust emissions (catalyst)2.8× usual
    Porsche Boxster
    7.4% All 2004 cars
    2.6%

    Failed outright at MOT: 7.4%, against 2.5% of all 2004 cars. The rest were advisories or minor defects.

    Rough price £175–£900 (catalytic converter) ClickMechanic

    At the viewing: Look for smoke when revving the warm engine and for engine or DPF warning lights.

Better than most

Engine oil leaks: 5.4% here, against 14.6% of all 2004 cars. Suspension arm bushes and joints: 1.1% here, against 9.4% of all 2004 cars.

Common 2004 Porsche Boxster MOT failures and advisories

The share of 2004 Porsche Boxster MOT tests where testers flagged each area, as a fail or an advisory. Rough prices are typical independent-garage costs.

  • Brakes
    31% of testsRough price £150–£350

    At the viewing: Look for a lip on the disc edges and feel for judder or pulling when braking firmly from about 40mph.

  • Lights and electrics
    18% of testsRough price £10–£80

    At the viewing: Ask a friend to check every light, including brake lights and indicators, while you operate them.

  • Tyres
    18% of testsRough price £70–£150

    At the viewing: Check the tread on all four tyres, including the inside edges, and look for cracks or bulges.

  • Suspension
    16% of testsRough price £120–£400

    At the viewing: Listen for knocks over speed bumps, and look behind each front wheel for a snapped coil spring.

  • Oil and fluid leaks
    7% of testsRough price £80–£600

    At the viewing: Look under the engine and on the ground where the car is usually parked for fresh oil or fluid.

  • Exhaust and emissions
    7% of testsRough price £100–£1,200

    At the viewing: Look for black soot in the tailpipe, listen for blowing from the exhaust and check for engine or DPF warning lights.

Questions to ask the seller before buying a 2004 Porsche Boxster

Ask before you travel to see it. A seller who knows the car will have answers, and receipts.

  1. Any recent work on the exhaust emissions (catalyst)? (Flagged at MOT 2.8× as often on the 2004 Porsche Boxster as on other cars the same age.)
  2. Can I see the service history and receipts for any big jobs?

Looking at a Porsche Boxster?

Check the actual car: its own MOT history, mileage and what to ask the seller. Free, no sign-up.

Other years

Every year of the Porsche Boxster compared

YearMOT testsMost flagged
2022281Tyres 14%
2021543Tyres 12%
20201,324Tyres 18%
20192,636Tyres 19%
20183,020Tyres 18%
20172,949Tyres 20%
20163,637Tyres 18%
20153,166Tyres 15%
20143,540Tyres 17%
20133,759Tyres 18%
20123,277Tyres 18%
20112,297Brakes 17%
20102,386Brakes 19%
20092,509Brakes 19%
20083,177Brakes 23%
20074,757Brakes 24%
20065,567Brakes 28%
20059,689Brakes 29%
20037,285Brakes 34%
20026,395Brakes 32%
20016,193Brakes 34%
20005,643Brakes 33%
19993,126Brakes 32%
19982,279Brakes 32%
19971,163Brakes 31%
1996–Too few tests

Where this comes from: the DVSA's anonymised results for every MOT test done in Great Britain during 2023–2025, counting the MOTs of Porsche Boxster cars first registered in 2004. "Flagged" includes advisories, so it isn't the same as a fail rate. How we score