Replacing the catalytic converter gasket (Priora 2170)

Between the flanges of the cylinder head and the exhaust manifold, a sealing gasket is installed, made of two thin molded metal strips connected to each other by spot welding. If the gasket is not tight, exhaust gases will break through to the outside, accompanied by a characteristic sharp sound. If the fault cannot be corrected by tightening the exhaust manifold mount, replace the gasket.

You will need: 10 and 13 mm wrenches, a 13 mm socket head, pliers, a ruler, and a feeler gauge.

1. Disconnect the wire from the negative terminal of the battery.

2. Remove the decorative engine cover (see "Removing and installing the decorative engine cover").

3. Disconnect the exhaust pipe of the additional muffler from the exhaust manifold by unscrewing the nuts securing the exhaust pipe flange to the exhaust manifold flange, disconnect the suspension cushions from the muffler brackets and remove the exhaust pipe flange from the exhaust manifold flange studs. Remove the additional muffler (see "Replacing the additional muffler").

4. Press the clamps…

5. …and disconnect the control and diagnostic oxygen concentration sensor wiring harness connectors from the engine harness.

6. Press the holders' antennae…

7. …and disconnect the holders of the control and diagnostic oxygen concentration sensor wire harnesses from the steering gear heat-insulating shield.

8. Using a 13 mm socket head, unscrew the bolts securing the exhaust manifold to the bracket.

9. Using a 10 mm spanner, unscrew the three nuts securing the steering gear heat-insulating shield to the engine shield (two nuts are located under the steering gear)…

10. …and remove the shield.

11. Using a 13 mm wrench, unscrew the two nuts securing the water pump inlet pipe bracket…

12. …and remove the bracket.

13. Using a 13 mm wrench, unscrew the eight nuts securing the exhaust manifold to the cylinder head…

14. …and remove the exhaust manifold…

15. …and its gasket.

16. Install the new gasket and all removed parts in the reverse order of removal.

17. Check the flatness of the exhaust manifold flange surface. To do this, place the ruler edgewise on the surface of the flange and measure the gap between the plane of the flange and the ruler with a feeler gauge. Grind the flange surface or replace the collector if the gap exceeds 0.1 mm.

Note: To prevent the gasket from sticking and to improve its tightness, we recommend that you lubricate the gasket on both sides with a thin layer of graphite grease before installation.