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Q: Main relay, EMS1 fuses, and EMS2 fuses are missing. Do I need these parts?

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main relay, EMS1 and EMS2 fuses are not there in place. still engine is working and getting average of 12km/litre. MIL is on with trouble codes ; P0340,P0404,P0135, and P0443. please advice if replacing the relays and fuses will rectify the problem?

My car has 23000 miles.
My car has a manual transmission.

Hi there. The codes are coming up for the camshaft position sensor, Oxygen sensor, EGR valve, and evaporative system not working. The fuses for EMS1 and EMS2 and the main relay vary depending on what Aveo model you have. If you have a hatch back, these are not required to have. If you have a sedan, then it’s required to have the fuses and the main relay. Without them on a sedan, the vehicle will not start up and will not have power to the vehicle. Check the circuits to the camshaft position sensor, and check the EGR valve for any signs of exhaust leaks or issues. For the evaporative system, check the gas cap and make sure that its sealing tight. Replace any sensor that has power to it but nothing coming out or the power does not change coming out. If you need further assistance with a poor fuel mileage and having the engine light on, then seek out a professional, such as one from Your Mechanic, to help you.

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