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P0401 Not enough exhaust gas recirculation flow

Generic SAE definitionExhaust gas recirculation flow insufficient detected

Safe to driveNormal 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.

  1. Clean the EGR valve and passages

    $156–$304

    Carbon blocks the flow; cleaning often fixes it outright.

  2. EGR valve

    $226–$594

    A valve that won't open any more.

  3. EGR cooler or tube

    $462–$1,288

    Blocked or cracked pipework on diesels and some turbo engines.

Code titles are the generic SAE definitions. Prices are typical US parts and labor for a common car or light truck – a guide for judging a quote, not a quote. Always confirm a repair against the vehicle in front of you.

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See what your vehicle says about P0401

A stored code is a headline, not the story. The vehicle also holds the conditions from the moment the code set, how close each part is to the limit it fails at, what the fuel trims are doing, and whether the fault is still happening. Drive DTC reads all of it with a USB adapter and a Windows PC – read-only by design.

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More in Emissions

All 12 codes in this group
P0420Catalyst system efficiency below threshold (Bank 1) P0430Catalyst system efficiency below threshold (Bank 2) P0441Evaporative emission system incorrect purge flow P0442Evaporative emission system leak detected (small leak) P0443Evaporative emission system purge control valve circuit P0446Evaporative emission system vent control circuit