Service Buddy
Emissions

Code P0401

EGR Flow Insufficient Detected

Plain English Meaning:Not enough exhaust gas is recirculated

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Yellow: Drive with Caution

Can lead to engine knock and efficiency loss

P0401 Symptoms

  • Check engine light knocking rough idle

Most Common Causes of P0401

1Clogged EGR valve faulty solenoid

P0401 Repair Playbook

Required Mechanic Tests

A qualified shop should perform these tests before replacing any parts to ensure they aren't guessing:

Command EGR inspect carbon buildup

Typical Fix Paths & Estimated Costs

Clean or replace EGR $150–$600

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Parts for P0401 Repair

Common replacement parts for emissions codes. (Paid links)

Oxygen (O2) Sensor
$25–$80 · Est. Price
Catalytic Converter
$150–$400 · Est. Price
EGR Valve
$40–$120 · Est. Price

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