Audi Workshop Service and Repair Manuals

Removing and installing front exhaust pipe with catalytic converter and front silencer Special tools and workshop equipment required

t  Lambda probe open ring spanner set -3337-

Removing –  Detach vacuum hose -2- from air intake hose (if fitted). –  Detach air hose -1- at the throttle valve module -J338-. –  Unplug electrical connector for air mass meter -G70- -item 3-. –  Unscrew air cleaner housing (upper section) -arrow-. –  Take out filter element.

–  Pull cover -1- off air duct (release clips on sides). –  Unclip air duct -2-.

–  Unscrew air cleaner housing (lower section) -arrows-.

–  Unplug electrical connectors -1- and -2- for Lambda probe -G39- (before catalytic converter) and Lambda probe 2 -G108- (before catalytic converter). –  Move electrical wiring to Lambda probes clear.

–  Unscrew Lambda probe 2 -G108--item 1- and Lambda probe -G39--item 2-.

–  Unscrew bolts -1- and -3- and remove support -2- for front exhaust pipe.

–  Unscrew nuts of front exhaust pipe which are accessible from above from exhaust manifolds -arrows-.

–  Remove centre noise insulation -fasteners 1 ... 3-.

–  Remove noise insulation (right-side) -fasteners 1 ... 3-.

–  Remove underbody cover (right-side) -arrows-.

–  Unplug electrical connectors -1- and -2- on underbody (right-side). –  Detach plug connector from bracket and move wire to Lambda probe after catalytic converter -G130- and Lambda probe 2 after catalytic converter -G131- clear.

–  Unscrew nuts of front exhaust pipe which are accessible from below from exhaust manifolds -arrows-.

–  Remove front cross member for underbody; to do so, unscrew nuts -1- and -2-.   Note To avoid damage, the flexible joints in the front exhaust pipe must not be bent more than 30°. –  Disconnect exhaust system at clamp -3-.

–  Unscrew bracket for exhaust system -arrows- and remove exhaust system. –  Remove front exhaust pipe with catalytic converter and front silencer. Installing Installation is carried out in the reverse order; note the following:   Note Renew gaskets and self-locking nuts. –  Align exhaust system so it is free of stress → Chapter. Tightening torques

Component	Nm
Front exhaust pipe to exhaust manifold	40 → Note
Catalytic converter to front exhaust pipe	23 → Note
Lambda probe in front exhaust pipe	55
Bracket for exhaust system to subframe	23

1)  Renew nuts and bolts.