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Actually the EGR (Exhaust Gas Recirculation) valve can be fix permanently. The EGR valve costs only $73.99 and it does come with a 2 year warranty. Also the EGR valve is not very hard to replace (only about 1hour of labor at most shops which is about $100 for installation). Once you replace the unit it will not keep going out on you on a monthly bases.
However, prior to changing any parts. I would strongly suggest that you do an OBDII scan on the car. Take the car to autozone and ask for an OBDII, this will tell you why the light came on and what needs to be fixed/replaced.