nissan frontier showing p0400 after erg valve replaced

Question

service engine light on after erg valve replaced

Answer 1

The P0400 code means that there is no EGR flow. The EGR flow is detected by the EGR temperature sensor. The first thing you need to do is to check if the EGR valve diaphragm is lifting when the engine is rev to above 2000 RPM. If the EGR is not lifting then you may have a problem with the EGR solenoid valve or the vacuum lines to the EGR valve. If the valve is lifting then the there is a EGR blockage.