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Q: Low power and rough running. Check engine light flashing but no codes at download.

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We have checked all plug wire connections and all are good. This just started a day or two after a couple 175 mile drives with no problems.

My car has 204000 miles.
My car has a manual transmission.

A: This may be caused by a few different thing...

This may be caused by a few different things such as dirty fuel injectors, low fuel pressure or a dirty or failing mass air flow sensor.

As you may know, dirty fuel injectors may cause intermittent fuel supply to the motor causing an unbalanced load of fuel and air to be supplied to the motor resulting in a rough running motor with a lack of power. Low fuel pressure may also cause this same kind of result due to an inefficient supply of fuel to the injectors.

The mass air flow sensor monitors the air intake as it is mixed with fuel prior to being injected into the motor. When this is not working properly, this may also cause an incorrect air/fuel mixture to be supplied to the motor resulting in poor fuel economy, rough running and lack of power. If you would like to have an expert scope this out in person, a qualified professional from YourMechanic can come to your car's location to diagnose the vehicle's loss of power and pinpoint the correct repairs.

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