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Q: Car misfiring, running rough.

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My car is running rough. The codes say I have a lean mixture and I am having misfires in the cylinders.

A: The lean codes on this engine could mean yo...

The lean codes on this engine could mean you have a lean condition that the computer sees as a problem. The computer would need to be scanned to see if the mass air flow sensor is reading correctly. The sensor normally gives a reading to the computer of the cars altitude or barometric pressure. If the reading output does not match the local pressure the sensor may need to be replaced. I have seen sensor readings equal to 10000 ft above sea level when I was at 10 ft above sea level. This will cause the computer to send less fuel to the computer and would cause lean codes. In this case, a mass air flow sensor replacement fixed it.

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