Fiat original exhaust system


Below is a description of the exhaust system on the B. On earlier model the system fitted by Fiat was quite heavy and did not last long. It was fo this reason that DTR in the UK designed their own system to replace the Fiat original.

2021 note. We don’t know if DTR still carry stocks for their exhaust system. Custom suppliers such as Longlife may be able to help.


  • The exhaust system starts underneath the front of the engine, just behind the radiator system

  • After the manifold has left the engine it passes between the oil sump and the gearbox.
  • On top of the exhaust at this point (in the yellow box) is the lambda sensor this tells the engine management system how much oxygen is in the exhaust gases and makes adjustments to the engine to make sure the fuel it has pumped into the engine is being burnt correctly. It also ensures the b is not generating too much polluting gases.

  • This is the catalytic converter with heat shield (the metal plate above it)

  • This is the first rear box in the system

  • This is the final silencer box before the system splits into a twin pipe

  • That just leaves the the twin pipes at the end

This technical guide was originally held at It was copied to this site in 2021 to ensure its availability and to reformat it into a more modern layout. The original guide was written by Ian Barnett.

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