Exhaust System: Description and Operation

Exhaust system E65, E66 N73/N73TU





Introduction
> N73
The exhaust system on the previous N62 engine has been adapted for the N73 engine

> N73TU with introduction 09/06
The N73TU satisfies the legal emissions limits, e.g. Euro 4 standard for Europe or LEV II for the USA (LEV: Low Emission Vehicle).
Measures on the exhaust system:
- new oxygen sensors
- 2 control sensors upstream of catalytic converter (LSU 4.9)
- 2 monitor sensors downstream of catalytic converter (LSF 4.2)


Brief description of components
The exhaust system consists of the following components:

- Exhaust flap
The exhaust flap controls the flow of exhaust gas in the rear silencer to reduce noise levels.

- 2 rear silencers
- intermediate silencer
- 2 front silencers
- 2 monitor sensors
- 2 broadband oxygen sensors
- 2 exhaust manifolds with preliminary and main catalytic converters

System functions
There are no new functions in the exhaust system of the N73, N73TU.

Notes for service staff
Service staff should note the following points:

- General information: ---
- Diagnosis: ---
- Encoding/programming: ---
Subject to change.