Blinking check engine light

Check engine light and flashing not a good thing.
Most likely it is misfiring and when it flashes you should not continue to drive.
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flashing engine light means pull over and shut it off! Because raw fuel(un burnt) is entering your catalytic converter. Best way is to scan the engine and find out which cylinder is misfiring! If it is 1.6l it could b a head gasket allowing coolant entering your cylinders, or go back to the same tech who did tune up and he should know why, he performed a tuneup!

Vacuum leak, intake manifold runner not operating properly because of vacuum leak. This happened to me and clogged my catalytic converter up. had to chunk it out and fix the problem. Used Seafoam on intake manifold and no smoke out the tail pipe, it came up from under the car which is how I figured out the cat was clogged. If you fix this vacuum leak or solenoid valve problem quickly enough the catalytic converter will not be damaged. The valve runner solenoid is located on the fire wall just below the MAP sensor, it has two wire plug and two vacuum lines on it. One supply and one that goes the the valve runner mechanical solenoid. At idle the valve should pull in, disconnect vacuum hose on it while at idle to check this.

High tension wires also cause this when insulation starts breaking down, wires arc to valve cover. You can check this by removing plastic cover with four allen screws and when it is dark out start the car and spray a mist of water from as spray bottle across the wires look for arcs. Replace spark plug wires if there are any.