Failure category
Exhaust & emissions
Exhaust splits, mounts, catalytic converters, transmission CV-joint boots, emissions-related faults.
Defect codes
28
Total fails
1,288,365
Defect codes in this category, ranked.
Sorted by total cars affected last year. Click any row for the full defect description plus the models most at risk.
- 01 696,706
A transmission shaft constant velocity joint boot severely deteriorated
604 models affected
- 02 452,004
A transmission shaft constant velocity joint boot missing or no longer prevents the ingress of dirt etc
397 models affected
- 03 109,161
Exhaust system leaking or insecure
138 models affected
- 04 12,701
Exhaust system leaking or insecure
23 models affected
- 05 11,789
Emissions levels exceed the manufacturer's specified limits
56 models affected
- 06 2,240
Emissions levels exceed default limits
26 models affected
- 07 1,283
Emissions levels exceed default limits
36 models affected
- 08 908
Emissions levels exceed default limits
25 models affected
- 09 514
Emissions test unable to be completed
20 models affected
- 10 268
Exhaust system leaking or insecure
13 models affected
- 11 250
Exhaust noise levels in excess of those permitted
23 models affected
- 12 202
Emissions levels exceed the manufacturer's specified limits
6 models affected
- 13 67
Emissions levels exceed default limits
8 models affected
- 14 61
Emissions levels exceed default limits
2 models affected
- 15 41
A transmission shaft flexible coupling excessively deteriorated
5 models affected
- 16 41
Emissions levels exceed default limits
12 models affected
- 17 33
A transmission shaft bearing excessively worn
6 models affected
- 18 19
An exhaust silencer marked ‘NOT FOR ROAD USE’, ‘TRACK USE ONLY’ or similar words
2 models affected
- 19 18
Emissions test unable to be completed
4 models affected
- 20 14
Exhaust noise levels in excess of those permitted
2 models affected
- 21 10
A transmission shaft bearing housing likely to fail
3 models affected
- 22 9
An induction or exhaust leak that could affect emissions levels
2 models affected
- 23 9
Exhaust system leaking or insecure
1 models affected
- 24 5
A transmission shaft bearing housing fractured or insecure
2 models affected
- 25 4
A transmission shaft bearing likely to break up
1 models affected
- 26 4
An induction or exhaust leak that could affect emissions levels
1 models affected
- 27 2
A transmission shaft constant velocity joint boot missing or no longer prevents the ingress of dirt etc
1 models affected
- 28 2
A transmission shaft constant velocity joint boot severely deteriorated
1 models affected
Brands most affected.
Total category-fails across each manufacturer's tested fleet. High-volume brands naturally lead — read alongside their model pass-rates.