Insufficient EGR: four cylinder. Replaced EGR Modulator and valve, Replaced some cracked vacuum hoses to the EGR components, and still can not clear the P0401 code. What should I check next? Looking at MAP/MAF sensor but everything I hear about this, says they rarely ever go bad…could this be it? Would this be the next component I need to replace? What else could cause this code to trigger? Failed emissions inspection twice now.
Thanks for all the help in advance!