Check Engine

On a 1994 530i the check engine light comes on occasionally and goes out when I rev the engine. What could cause this?

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air flow sensor perhaps.

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Bob wrote:

Oil pressure maybe?
Alternator output low?
Good luck with it and do let us know what you find.
Cheers, Bob
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Check the code. Jim
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It could be caused by any number of things. There is a sequence where you turn the ignition ON, then fully depress the gas pedal and release it again 5 times, the Check light then will flash a code. Write the code and we can help you figure out what it means.
My GUESS is that your O2 Sensor is going to report an error. Since the O2 Sensor lives in a very hostile environment, I further guess the sensor has failed, and the stuff it checks is okay. You need to know the fault code to see if my guess is correct. Alternatively, you could replace the sensor and see if that fixes the light, but blindly twisting screws and bolts is not really the right action when the car is willing to tell you what is wrong.

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