Evaporative Emission System Leak Detection Reference Orifice Low Flow
This code means the PCM/ECM has detected a leak in the system affecting evaporative emission. This can keep the emissions system from working correctly, which may raise tailpipe emissions, reduce fuel economy, and prevent readiness monitors from completing.
What You Might Notice
- Check Engine Light illuminated
- Rough idle
- Hesitation on acceleration
- High or unstable idle
- Lean-running symptoms or hissing noise
Most Common Causes
- 1
Vacuum leak or loose intake duct
- 2
Cracked PCV, brake-booster, or vacuum hose
- 3
Leaking intake manifold gasket
- 4
Faulty or dirty airflow sensor skewing fuel trims
- 5
Damaged intake plumbing after the MAF
How to Diagnose It
- 1
Check Vacuum leak or loose intake duct — Inspect for signs of failure and test before replacing.
- 2
Check Cracked PCV, brake-booster, or vacuum hose — Inspect for signs of failure and test before replacing.
- 3
Check Leaking intake manifold gasket — Inspect for signs of failure and test before replacing.
- 4
Check Faulty or dirty airflow sensor skewing fuel trims — Inspect for signs of failure and test before replacing.
- 5
Check Damaged intake plumbing after the MAF — Inspect for signs of failure and test before replacing.
How to Fix It
- 1
Inspect the sensor, valve, heater, and related hoses or pipes
- 2
Repair wiring or connector damage
- 3
Clean carbon buildup or repair leaks/restrictions
- 4
Replace the failed emissions component if testing confirms it
- 5
Clear the code and run the monitor to verify the fix
Need a deeper diagnosis?
Search for related repair guides or browse by system.