What does code P1491 mean?

Q: What does code P1491 mean?

EGR Valve Lift Insufficient Detected. P1491 is a Honda-specific code indicating that the powertrain control module (PCM) commanded the exhaust gas recirculation (EGR) valve to open to a specific lift, but the valve did not achieve the expected lift within the allowed time. The PCM monitors EGR valve position via a lift sensor and sets this code when the actual lift falls short of the commanded value, typically due to carbon buildup, a faulty valve, or a wiring issue.

DTC codes / Honda codes / P1491

P1491 · HondaEGR Valve Lift Insufficient Detected

P1491 is a Honda-specific code indicating that the powertrain control module (PCM) commanded the exhaust gas recirculation (EGR) valve to open to a specific lift, but the valve did not achieve the expected lift within the allowed time. The PCM monitors EGR valve position via a lift sensor and sets this code when the actual lift falls short of the commanded value, typically due to carbon buildup, a faulty valve, or a wiring issue.

SystemPowertrain

Code typeHonda specific

SeverityMedium

Fix difficultyIntermediate

AreaAuxiliary emission controls

Guidance is general and written for Honda vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.