Used car guide

2004 Porsche Boxster: common problems and what to check

What gets flagged at MOT on 2004 Porsche Boxsters, from 1,997 tests in 2025, plus known faults and what to look at before you buy one.

1,997MOT tests in 2025
76%pass first time (all 2004 cars: 58%)
3,700typical miles a year
3.1×the usual rate for exhaust emissions (catalyst)

What stands out

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

  • Exhaust emissions (catalyst)3.1× usual
    Porsche Boxster
    8.1% All 2004 cars
    2.6%

    Failed outright at MOT: 8%, 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: 5.9% here, against 15.8% of all 2004 cars. Tread depth: 9.3% here, against 18.7% of all 2004 cars.

By area

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
    30% 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
    17% 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
    15% 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.

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Other years

YearMOT testsMost flagged
2019885Tyres 17%
20181,010Tyres 17%
2017986Tyres 20%
20161,232Tyres 17%
20151,080Tyres 17%
20141,202Tyres 17%
20131,256Tyres 17%
20121,099Tyres 20%
2011777Brakes 19%
2010811Brakes 18%
2009859Brakes 20%
20081,049Brakes 23%
20071,568Brakes 25%
20061,848Brakes 27%
20053,214Brakes 30%
20032,380Brakes 33%
20022,091Brakes 32%
20012,024Brakes 34%
20001,853Brakes 34%

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