Removing and refitting the catalytic converter (F4R engine)
Preliminary operation: to remove the pre-catalytic converter, remove the engine.
Unscrew the securing bolts and remove the heat shield (Fig. 1).
Removal sequence:
- Disconnect the wire connectors from the oxygen sensors.
- Remove the upper mounting bracket and the upper strut.
- Remove the bracket securing the catalytic converter strut on the gearbox.
1 — oxygen sensors; 2 — upper mounting bracket; 3 — upper strut;
4 — strut securing bracket; 5 — catalytic converter securing nuts
Unscrew the nuts securing the catalytic converter to the turbocharger and remove the catalytic converter (Fig. 2). Remove the oxygen sensors on the workbench.
Subject to mandatory replacement: the sealing gaskets of the exhaust pipe flange and the turbocharger.
Refitting
Refit the oxygen sensors.
Tightening sequence:
- Screw in until contact in the specified sequence:
- the bolts securing the upper mounting bracket;
- the nuts securing the catalytic converter to the turbocharger;
- the bolt securing the catalytic converter to the upper strut.
- Tighten in the specified sequence to the required torque.
Tightening torques:
- bolt securing the catalytic converter to the upper strut — 8.5 N·m;
- bolts securing the upper lug to the exhaust manifold — 8.5 N·m;
- bolts securing the upper lug to the pre-catalytic converter — 8.5 N·m;
- nuts securing the catalytic converter to the turbocharger — 40 N·m;
- oxygen sensors — 34 N·m;
- studs of the exhaust pipeline flange securing — 8.5 N·m;
- bolt securing the upper strut to the engine — 38 N·m.
Refitting is carried out in the reverse order to removal.
Additional information: for more detail see the article Replacing the silencers and pipes on a Renault Megane 2.
Removing and refitting the catalytic converter (K4J, K4M engines)
Precautions:
- Place the vehicle on a two-post lift.
- Disconnect the leads from the battery terminals, starting with the negative terminal.
- Remove the engine sump guard.
- Remove the lower oxygen sensor.
Cut the exhaust pipeline.
Unscrew the nuts securing the exhaust pipeline flange and remove the catalytic converter (Fig. 3).
Refitting
Important requirements:
- Do not use a previously used sleeve.
- When assembled, the sleeve bolt and nut must not touch the body floor.
- A damaged heat shield is subject to mandatory replacement.
- Always replace the exhaust pipeline flange gasket and all disconnected plastic intake air ducts.
Refitting sequence:
- Refit the lower oxygen sensor.
- Tighten the oxygen sensor using the tool (Mot1495-01) to a torque of 45 N·m.
- If necessary, tighten the studs of the exhaust pipeline flange securing to a torque of 7 N·m.
- Refit the catalytic converter and the sleeve.
- Tighten the nuts securing the exhaust pipeline flange to a torque of 21 N·m.
- Tighten the sleeve, relieving the exhaust pipeline to align it.
- Connect the oxygen sensor.
Check after refitting:
- Make sure all the heat shields of the exhaust system are present and securely fastened.
- Make sure the exhaust pipeline does not touch the body floor.
Refit the engine sump guard. Reconnect the leads to the battery terminals, starting with the positive terminal.
Additional information: for more detail see the article Replacing the silencers and pipes on a Renault Megane 2.
Removing and refitting the additional silencer (all engines)
Precautions: place the vehicle on a lift. Remove the engine sump guard.
Cut the exhaust pipeline.
Unscrew the bolts securing the additional silencer to the cushion bracket and remove the additional silencer (Fig. 4).
Note: if the suspension cushions are damaged, mark the position of the bracket on the body, then replace the suspension cushion together with the bracket.
Refitting
Cut the pipe of the new additional silencer to size. Refit the additional silencer and the sleeve.
Tightening torques:
- bolts securing the suspension cushion bracket to the additional silencer — 8 N·m;
- bolts securing the suspension cushion bracket to the body — 21 N·m.
Tighten the sleeve, relieving the exhaust pipeline to align it.
Check after refitting:
- Make sure all the heat shields of the exhaust pipeline are present and securely fastened.
- Make sure the exhaust pipeline does not touch the body floor.
Additional information: for more detail see the article Replacing the silencers and pipes on a Renault Megane 2.
Removing and refitting the main silencer (all engines)
Precautions: place the vehicle on a two-post lift.
Cut the exhaust pipeline.
Unscrew the bolts securing the main silencer to the suspension cushion bracket and remove the main silencer (Fig. 5).
Refitting
Refit the main silencer and the sleeve.
Tightening torques:
- bolts securing the suspension cushion bracket to the silencer — 8 N·m;
- bolts securing the suspension cushion bracket to the body — 21 N·m.
Tighten the sleeve, relieving the exhaust pipeline to align it.
Check after refitting:
- Make sure all the heat shields of the exhaust pipeline are present and securely fastened.
- Make sure the exhaust pipeline does not touch the body floor.
Additional information: for more detail see the article Replacing the silencers and pipes on a Renault Megane 2.