Drive DTCP0401 – Not enough exhaust gas recirculation flow
Exhaust gas recirculation flow insufficient detected
Emissions · generic OBD-II code
Normal driving is fine. Book it in when it suits you; it won't hurt anything in the meantime.
Check this first
Ask for the EGR valve and passages to be cleaned before anything is replaced – they clog with soot.
What usually fixes it
In the order a good shop checks them. Typical total: $156–$1,288 at $130 an hour.
Clean the EGR valve and passages
Carbon blocks the flow; cleaning often fixes it outright.
EGR valve
A valve that won't open any more.
EGR cooler or tube
Blocked or cracked pipework on diesels and some turbo engines.
What the vehicle can tell you itself
A stored code is a headline, not the story. The vehicle also holds the conditions when it happened, how close the part is to the limit it fails at, what the fuel trims are doing, and whether the fault is still happening right now. Drive DTC reads all of it with a USB adapter and a Windows PC – and it can't change a single setting on the vehicle.
See what your vehicle says about P0401
Codes in plain English, what usually causes them, what the repair costs, and whether it's safe to drive.