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
1998 Acura 3.5RL Special EditionSECTION DTC P0401: EGR System - Insufficient Flow Detected
WARNING: This page is about a different car, the 1998 Acura 3.2TL. However, it is still accessible from the selected car via links, so may be relevant.
- If DTC P0401 is set, check for a clogged or leaking Exhaust Gas Recirculation (EGR) vacuum line, or a faulty EGR valve. Repair or replace components as necessary. If no problems are found, go to next step.
- Perform PCM reset procedure. See PCM RESET PROCEDURE/CLEARING CODES under SELF-DIAGNOSTIC SYSTEM. Install SCS Service Check Connector Tool (07PAZ-0010100). See Figure. Test-drive vehicle with no electrical load, with A/T in "D4" position. Decelerate gradually from 55 MPH for at least 5 seconds. If DTC P0401 resets, go to next step. If DTC P0401 does not reset, problem is intermittent. System is okay at this time.
- Clean intake manifold EGR port and EGR passage with carburetor cleaner. Clean passage inside EGR valve with carburetor cleaner, or replace EGR valve as necessary.
RENDER: 1.0x
NO RELATED
Recommended Tools & Savings
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.