Reasons for rejection

Mandatory equipment

1. A vehicle is not fitted with an exhaust system that includes a means of sound reduction (Note 1).

Condition

2. An exhaust system is not securely mounted.

3. The exhaust system is so constructed or modified that its operation or effectiveness can be readily interfered with.

4. The exhaust system is so constructed that emitted heat or fumes are likely to harm vehicle occupants, eg the exhaust gases are not directed away from the perimeter of the vehicle’s passenger compartment.

Performance

5. There is a leak of exhaust fumes from the exhaust system.

6. The noise output is noticeably and significantly louder than it would have been when the vehicle was manufactured with its original exhaust system.

Note 1

Exhaust system means a pipe assembly through which the engine exhaust gases pass to the atmosphere and includes some means of sound reduction such as a silencer or resonator.

Note 2

A spark arrestor is not required to be checked.

Summary of legislation

Applicable legislation

• Land Transport Rule: Vehicle Equipment 2004.

Mandatory equipment

1. A tractor with an internal combustion engine must be fitted with an exhaust system (Note 1).

Condition

2. An exhaust system must not be constructed or modified in a way that allows a person to interfere readily with its operation or reduce its effectiveness.

3. An exhaust system must be designed, constructed, positioned and maintained in a way that minimises the risk of heat or fumes emitted from the system harming the vehicle’s occupants.

Performance

4. An exhaust system must be effective and in good working order.

5. Noise from an exhaust system must not be noticeably and significantly louder than it would have been when the vehicle was manufactured with its original exhaust system.

Reasons for rejection

Performance

1. A vehicle with the engine at normal operating temperature emits clearly visible smoke (Note 2) from the exhaust tail pipe during a rapid acceleration test (Note 1).

Note 1 Test procedure

Rapid acceleration test

While the engine is accelerated quickly from idle to 2500rpm (or half the maximum engine speed if this is lower), observe the tailpipe emissions. To avoid engine damage do not over-accelerate the engine. A vehicle that passes this test below normal operating temperature is deemed to have passed with the engine at normal operating temperature.

Note 2

Visible exhaust smoke does not include:

• emissions that are largely water vapour, or
• smoke that is barely visible, or
• a moderate amount of smoke caused by turbo lag, or 
• some normal visible smoke caused by the engine's design (with the engine in good condition and running the correct fuel). The inspector may require documentary evidence that the engine produces some visible smoke because of its design.

Note 3

The vehicle inspector may need to take into account information from the vehicle manufacturer or their representative or other appropriate expert, eg about older or unusual vehicles.

Summary of legislation

Applicable legislation

• Land Transport Rule: Vehicle Exhaust Emissions 2007.

Performance

1. A tractor must not emit clearly visible smoke when the engine is running at its normal operating temperature, under the following condition: