Alfa Romeo klub Srbija

The engine exhaust gases flow into two doueble manifolds (1) integral with the catalytic preconverters (2) and the catalytic converters (3) and from there into the front section of the exhaust pipe (4).

The front section of the exhaust pipe contains a flexible component (5) to limit the transmission of vibrations.

The rear section of the exhaust pipe consists of two silencers (6) connected by an intermediate exhaust pipe (7).

Special guards limit the radiation of heat towards the bodyshell.

The various components are supported by mountings and rubber rings secured to the underbody.

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Both lambda sensors upstream of the catalytic converters are linear, while the downstream sensors are planar and inform the control unit about the progress of combustion (stoichiometric ratio).

The upstream sensors (? 0.7 2.0) carry out the check on the mixture strength (except during idling) known as the 1st loop (upstream sensors closed loop).

The sensors downstream of the catalyzer are used for the catalyzer diagnosis and for finely modulating the 1st loop control parameters.

With this in mind, the adjustment of the second loop is designed to recover both production differences and those in the response of the upstream sensors which may occur as a result of ageing and pollution.
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