my 2003 escaladeis setting 3 codes po101 po171 po174 is maf po101 setting off the 02 sensors also also it will idle rough at times or even die at timesat low idle
Yes it could be a bad mass air sensor but my book said (circuit range performance problem).To me that is saying the mass air is bad and yes it can make the o2 sensors read wrong and set codes.Clear the codes and unhook the mass air plug and take it out of the hose and start it and let it run at idle to see if it runs better if so then lean towards a new mass air sensor.But it may or will set a new code beings it is unhooked.