Idle

My 1994 Ford Exploer XL Manual with 132000 dies when I let it idle. This problem does not always happen. My Check engine light had been on for a year before this problem occured and my mechanic said the EGR code he got was harmless and when I wanted I could do the work myself. When the idle problem started I got a full tune up and got the codes read again. I got codes for the MASS sensor and the EGR valve. I replaced the EGR and cleaned the MASS along with the Idle Air Control Valve. I did not get any codes for the idle componetes or the Oxy sensor. My check engine light is still on and I still recive some EGR codes. Should I replace the EGR solinoid next or will that not solve my idel problem? I realize I should take care of the check engine light problem, however the idle is a more pressing matter.