Removing and installing starter catalytic converters, intermediate pipes and main catalytic converters — AUDI
Removing and installing starter catalytic converters, intermediate pipes and main catalytic converters on Audi: factory workshop procedure for engines.
Workshop procedure for AUDI — the factory write-up, straight from real workshop data.
🔧 Engine codes this applies to
📋 Procedure
ℹ️ Torque figures below come verbatim from workshop data — always cross-check against your vehicle's factory manual before final tightening.
Audi
Audi A8
1994
Power unit
12-cylinder engine, mechanics
Edition
12.2004
Removing and installing starter catalytic converters, intermediate pipes and main catalytic converters
Note
The illustration shows the starter catalytic converters, intermediate pipe and main catalytic converter for cylinder bank 2 (left-side).
23 Nm
Renew
Seal
Sensitive to impact, do not drop
Starter catalytic converter (lower)
Removing, installing and adjusting
Chapter
Protect from damage by knocks and impacts
23 Nm
Renew
Special bolt
Renew
Note installation position
Exhaust manifold (front)
Removing and installing
Chapter
Lambda probe (before catalytic converter), 55 Nm
Threads of new lambda probes are already greased with assembly paste; the paste must not get into the slots on the probe body
When re-using the old lambda probe, grease thread with high-temperature lubricant; the paste must not get into the slots of the probe body; High-temperature lubricant
Parts catalogue
Removing and installing
Motronic injection and ignition system (12-cyl.)
Rep. Gr.
24
Lambda probe (after catalytic converter), 55 Nm
Threads of new lambda probes are already greased with assembly paste; the paste must not get into the slots on the probe body
When re-using the old lambda probe, grease thread with high-temperature lubricant; the paste must not get into the slots of the probe body; High-temperature lubricant
Parts catalogue
Removing and installing
Motronic injection and ignition system (12-cyl.)
Rep. Gr.
24
23 Nm
Renew
Special bolt
Renew
Note installation position
Exhaust manifold (rear)
Removing and installing
Chapter
Lambda probe (before catalytic converter), 55 Nm
Threads of new lambda probes are already greased with assembly paste; the paste must not get into the slots on the probe body
When re-using the old lambda probe, grease thread with high-temperature lubricant; the paste must not get into the slots of the probe body; High-temperature lubricant
Parts catalogue
Removing and installing
Motronic injection and ignition system (12-cyl.)
Rep. Gr.
24
Starter catalytic converter (upper)
Removing, installing and adjusting
Chapter
Protect from damage by knocks and impacts
Lambda probe (after catalytic converter), 55 Nm
Threads of new lambda probes are already greased with assembly paste; the paste must not get into the slots on the probe body
When re-using the old lambda probe, grease thread with high-temperature lubricant; the paste must not get into the slots of the probe body; High-temperature lubricant
Parts catalogue
Removing and installing
Motronic injection and ignition system (12-cyl.)
Rep. Gr.
24
23 Nm
Renew
Intermediate pipe
With flexible joint
Do not bend flexible joint more than 10° - otherwise it can be damaged
Removing, installing and adjusting
Chapter
Mounting components
Fig.
23 Nm
Renew
Main catalytic converter
Removing, installing and adjusting
Chapter
Protect from damage by knocks and impacts
Gasket
Renew
Mounting components for intermediate pipe
Bolt -25 Nm-
Washer
Compression spring
Spacer sleeve
Spacer sleeve
Bracket
Buffer
Washer
Bolt -25 Nm-
Note
The collar of the spacer sleeve
Item 4
must face the intermediate pipe.
The collar of the spacer sleeve
Item 5
must face the gearbox support.
TorqFix answers live for your specific car — tell it the engine code and it serves the matching sequence, torque figures and wiring for that exact variant.
Ask about my car →Other AUDI procedures
- Checking lambda control and lambda probes; operations for cylinders 1 to 6
- Draining · 1 torque figures
- Checking the data exchange between the engine control units and other CAN-capable control units
- Removing and installing right section of intake manifold
- Removing and installing top section of intake manifold
- Removing and installing toothed belt · 56 torque figures
- Removing engine · 41 torque figures
- Removing camshaft timing chain from camshafts · 38 torque figures
- Installing engine · 36 torque figures
- Removing and installing camshaft timing chain · 29 torque figures
Who makes these pages, and how
TorqFix was built by a mechanic — after a 2,700 km drive with five roadside repairs that no diagnostic tool could explain.
The figures on this page come from manufacturer workshop documentation and are shown as they are. The page is assembled automatically from that data — it is not written by an AI. The AI works in the chat, where it answers for your specific car. It writes nothing here.
Variants of the same model differ. Cross-check torque against the factory manual for your engine before final tightening.
Seen a figure that does not match your manual? Write to us — we correct it and note when. support@torqfix.com
The story behind TorqFix →Workshop data on this page last updated 20 Sep 2026.