The code: P0401 - EGR flow insufficient detected
This code gets triggered where there is an issue with the EGR Valve, typically when the valve is stuck closed or have excessive internal resistance.
The other code P0452 and P0401 are not directly related.
You can test the EGR valve to make sure it is functioning properly. It is possible that the EGR valve and tube just need to be cleaned out as it could have restriction due to being dirty.
Here is a helpful vide of testing a EGR Valve:
I have attached the P0401 basic diagnostics and the EGR diagrams below.
Please let me know of any questions.
Images (Click to enlarge)
Monday, October 11th, 2021 AT 6:50 AM