I have a 1999 Rodeo V6 that is idleing rough and stalling. The first codes
I was getting were mass air flow sensor and EGR valve as stated by the shop I took it to. I cleaned the EGR valve as recomended and the CEL came back on the next day so I cleaned the EGR again with the same results. Next I replaced the EGR valve (and purchased a code reader) and everything seemed ok until the next day I got codes 171 and 174. Still rough idleing and stalling. Where do I go next?

Sounds like an IMG leak. The P0171 was the code I got when mine went bad. Same with the rough idle. Your EGR valve is probably still good.

marc