engines codes please help

[jwilson2916]

i have a 95 mustang cobra 5.0. i recently failed emissions, to much nox. i tested it and got codes 172:Heated oxygen sensor indicates lean condition, right side... 175: heated oxygen sensor unable to swich, left side....and 334 EGR valve position sensor voltage above closed limit....can anyone lead me the the right direction

 

[HISSIN50]

Check the EGR position sensor voltage with the key on, car off. It should be about 1/2 volt.

Be sure you dont have any vac leaks. Look for ~20" hg of vac at idle.

 

[desertcox05]

try cleaning the maf too, and if all else fails pull the spout, drive it like that to get tested, after it passes then plug the spout back in. that's what i had to do to get it to pass

 

[jwilson2916]

thanks guys ill try it out