P1491 – Infiniti DTC

Infiniti DTC P1491 – EGR Valve Lift Insufficient Detected

DTC P1491 meaning on Infiniti

1. DTC P1491 indicates that the Engine Control Module (ECM) has detected insufficient EGR (Exhaust Gas Recirculation) valve lift.

Infiniti DTC P1491 symptoms

• Check Engine Light (CEL) illuminated on the dashboard.
• Reduced engine performance.
• Possible rough idling or stalling.

Infiniti DTC P1491 causes

1. Malfunctioning EGR valve.
2. Clogged EGR passages.
3. Faulty EGR position sensor.
4. Wiring or connector issues in the EGR system.

Infiniti DTC P1491 seriousness

1. While the vehicle may still be operable with this issue, it can lead to reduced fuel efficiency and increased emissions.
2. Continued driving with a malfunctioning EGR system can potentially cause damage to other engine components.

How to diagnose DTC P1491 on Infiniti

1. Use a scan tool to retrieve the DTC and freeze frame data.
2. Inspect the EGR valve and related components for any visible damage or blockages.
3. Check the EGR position sensor for proper operation.
4. Test the EGR system for vacuum leaks or electrical faults.

How to fix DTC P1491 on Infiniti

1. Clean or replace the EGR valve if it is found to be faulty.
2. Clean out any clogged EGR passages.
3. Replace the EGR position sensor if necessary.
4. Repair any wiring or connector issues in the EGR system.

How to erase DTC P1491 on Infiniti

1. After the issue has been fixed, use a scan tool to clear the DTC and reset the Check Engine Light.
2. Ensure that the repair has resolved the underlying problem causing the DTC.