Volkswagen Golf Service & Repair Manual: Exhaus system

Removing and installing engine control unit -J623- (with protective housing)

Special tools and workshop equipment required     Hot air blower -VAS 1978/14A--item 1- with nozzle - ...

Exhaust pipes, silencers

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Other materials:

Removing and installing engine speed sender -G28-
Special tools and workshop equipment required     Socket AF 4 mm -T10370- Removing –  Remove noise insulation → General body repair ...

Removing and installing steering column electronics control unit -J527-, Kostal
  Note Airbag coil connector and return ring with slip ring -F138- is integrated in steering column electronics control unit -J527-. When renewing the control unit, select “Renew” function for the respec ...

Is the smell coming from evaporator or the heat exchanger?
Fishy smell –  Due to leak in engine's cooling system or in heat exchanger of heater and air conditioner unit.   Note If the fishy smell is weaker when the temperature is set to “cold” or st ...