Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
DTC P0401: EGR System Insufficient Flow Detected
Perform PCM reset procedure. See PCM RESET PROCEDURE/CLEARING CODES under SELF-DIAGNOSTIC SYSTEM. Connect SCS service connector. Test drive vehicle with no electrical load at 55 MPH. Decelerate from 55 MPH for at least 5 seconds. If DTC P0401 does not set, problem is intermittent. System is functioning properly at this time. If DTC P0401 resets, clean intake manifold EGR port and clean or replace EGR valve.
NO RELATED
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.