Check engine light flash on and off what do I need to do

You can pull the check engine codes codes with out going to a shop. You need to short your Assembly Line Diagnostic Link (ALDL) with a paper clip or jumper wire. Find your ALDL; it should be a black connector, with 12 holes, in the passenger compartment, under the dash. There is raised notch that signifies the top of the connector (the connector may be upside down). With the connector right side up, insert a paper clip, or jumper wire, into the last two holes on the right side of the top row. Turn the ignition to the run position, but DO NOT START the car. The check engine light will begin to flash. It will flash several times to signify the first digit of a two digit code. It will then pause and flash several more times to indicate the final digit. The first code that will come out is 12 (1 flash followed by a pause and two more flashes), this code is no tach pulse (no engine RPM), and since the engine will not be on you can ignore it.

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Go to a local auto store like Auto Zone and they will read them for free...