P0401 code. (Actually a Mazda B2300) Checked EGR Valve and replaced stuck modulating solenoid. Vac lines checked good too. What should I be checking, and how? Vehicle runs fine except for the light, but emissions test due at end of month.
P0401 Low EGR Flow. Valve OK, stuck Solenoid replaced How to trouble shoot? on 1996 Ford Ranger
possibly clogged EGR passages.