OBD-II code · Powertrain (generic)
P016C Closed Loop Air/Fuel Ratio Control At Limit - System Too Lean
Closed-loop fuel trim hit its rich correction limit because mixture is structurally too lean. Likely vacuum leak, low fuel pressure, or contaminated MAF.
Is it safe to drive with P016C?
The car may go into limp mode (reduced power). Get it diagnosed before a long trip.
Common causes
- Most likelyVacuum leak
Symptoms
- Check engine light on
- Rough idle, possible stalling
- Hesitation or hard cold start
- Power loss under load
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.5–5 h
- Emissions test
- Likely to fail
- After the fix
- A drive cycle is needed before the light stays off
- Parts involved
- Intake System, Fuel Pressure Regulator, Mass Air Flow Sensor
Related codes
- P0169Incorrect Fuel Composition
- P016AExcessive Time To Enter Closed Loop Air/Fuel Ratio Control
- P016BClosed Loop Air/Fuel Ratio Control At Limit - System Too Rich
- P016DExcessive Time To Enter Closed Loop Fuel Pressure Control
- P016EClosed Loop Fuel Pressure Control At Limit - Pressure Too High
- P016FClosed Loop Fuel Pressure Control At Limit - Pressure Too Low
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.