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.
"Bob" <balbert3 RemoveThis @verizon.net> wrote in message
news:3CXeh.712$IO5.318@trnddc01...
> On a 1994 530i the check engine light comes on occasionally and goes out
> when I rev the engine. What could cause this?
>> Stay informed about: Check Engine