Mazda RX-8 common problems and MOT failures

What usually goes wrong with a Mazda RX-8?

We haven’t found widely reported faults for the Mazda RX-8 in the UK buying guides we use yet. That doesn’t mean it has none, so check the car carefully and look at the MOT weak spots below.

Common Mazda RX-8 MOT failures to check

Parts flagged at MOT well above the usual rate for cars the same age, in more than one year. From the DVSA’s results for every MOT done in Great Britain during 2023–2025.

• Exhaust emissions (catalyst)

  up to 3.6× usual

  Stands out on cars registered in 2004, 2005, 2006, 2007, 2008 and 2009.

  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.

• Engine warning light

  up to 2× usual

  Stands out on cars registered in 2004 and 2005.

  Rough price £10–£80 our estimate

  At the viewing: Ask a friend to check every light while you work the switches: indicators, brake lights, fog lights and reversing lights.

Mazda RX-8 MOT pass rate by year

Of the years since 2005 with plenty of MOT tests, the 2009 Mazda RX-8 did best (72% passed first time, 13 points above all 2009 cars) and the 2006 did worst (65%, 9 points above all 2006 cars). Older cars fail more, so compare each year with all cars registered the same year.

Questions to ask the seller before buying a Mazda RX-8

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 3.6× as often on the Mazda RX-8 as on other cars the same age.)
2. Any recent work on the engine warning light? (Flagged at MOT 2× as often on the Mazda RX-8 as on other cars the same age.)
3. Can I see the service history and receipts for any big jobs?