O2 Sensors

Shown On Engine 119.985:

Shown on engine 112, 113 in model 220:

Shown on engine 137.970:

Shown in model 203 with engine 112:

A total of 8 O2 sensors are installed upstream and downstream of the firewall catalytic converters (157). The longitudinal compensation element (156) is necessary because of the cylinder shutoff system if the left and right exhaust lines heat up to a differing extent.

The cross connection (a) prevents the left underfloor catalytic converter cooling down in the case of cylinder shutoff ON.

Location
- At underfloor

Purpose
- Directing exhaust gases with a low back pressure to the rear of the vehicle
- Noise insulation of exhaust gases
- Emission control by means of TWC

Purpose
- Directing exhaust gases with a low back pressure to the rear of the vehicle
- Noise insulation of exhaust gases
- Emission control by means of TWC

Design/function
- Front exhaust system with catalytic converter (with front muffler on models without TWC).
Firewall catalytic converters on engine 112, 113 (USA) and EURO3/4
- Center muffler
- Rear muffler with tail pipe
Partially double-walled for noise insulation, shields prevent heat being radiated to the underfloor