Having trouble with my car. When it is on a red light or stop sign it likes chokes like it stalls, its not giving fuel. I tap the gas pedal and it goes. I took it to the shop a couple of months ago to a merchanic and he said it was the Egr valve. He cleaned it it looked dirty. So he said, If it gave me more problems that i would have to replace it and buy a new one. Is this mechanic saying the truth about my car. Ive changed fuel filter, spark plugs, wires. Whats wrong with my car?