96 caddy. got a egr code a year ago. p1406. egr pintle stuck open. idled poor. took it off, gave it a smack and it reseated itself. the other day, i was on the highway and got behind a slowpoke and took my foot off the gas and than punched it and the engine hiccuped and check engine light came on. code 1406 and 0101. thats for a maf sensor error? got home and cleared code but 1406 would not clear. engine seemed to idle ok. i got a screwdriver and smacked egr again and than cleared code. i don't think 1 key cycle is enough to clear code? i did have egr off before and port does not seem dirty. it is an electric solenoid so i assume it could fail. anyone know how common it is to replace egr valves on newer cars?