The engine light came on a week age and then off without any repair done. It came back on two days ago and is still there. A friend helped to check and came up with codes P1410 and 1411, both pointing to EGR value position sensor problem. I have gone thru' this forum and different members have proposed different solutions ranging from using better quality gas, cleaning the exhaust system, replacing the sensor or even the entire EGR valve. Can anyone here recommend a more systematic way of repair ranging from doing it myself without buying any parts to buying and replacing the entire ERG valve, if necessary? TY.