1. Open the hood of the car.
2. Locate the fuel line that runs from the fuel tank to the engine.
3. Follow the fuel line to the fuel filter.
4. The fuel filter is usually a cylindrical-shaped component located near the fuel tank.
5. It may have two fuel lines connected to it, one from the fuel tank and one to the engine.
In Opel Astra J:
1. Open the hood of the car.
2. Locate the fuse box.
3. Remove the cover of the fuse box.
4. Locate the fuel pump relay.
5. Remove the fuel pump relay.
6. Locate the fuel filter.
7. The fuel filter is located under the fuel pump relay.
8. It may have two fuel lines connected to it, one from the fuel tank and one to the engine.
