OBD-II code · Powertrain (generic)
P046C EGR Sensor A Circuit Range/Performance
EGR sensor A reads in range but plausibility check fails — slow response or stuck reading. EGR mixes inert exhaust into intake to lower combustion peak temperature — too little raises NOx, too much causes misfires and rough running.
Is it safe to drive with P046C?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelySensor drift
- Less likelySensor element aged beyond calibration window
- Less likelySensor mounting loose - signal damping
Symptoms
- Check engine light on
- Pinging or knocking under load
- Power loss and hesitation
- Possible rough idle
- Failed emissions inspection (NOx)
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.5–2.5 h
- Emissions test
- Likely to fail
- Parts involved
- Egr Valve
Related codes
- P044BEGR Sensor C Circuit Range/Performance
- P046EEGR Sensor B Circuit Range/Performance
- P0469EVAP Purge Flow Sensor Circuit Intermittent
- P046ACatalyst Temperature Sensor 1/2 Correlation (Bank 1)
- P046BCatalyst Temperature Sensor 1/2 Correlation (Bank 2)
- P046DEGR Sensor A Circuit Intermittent/Erratic
- P046FEGR Sensor B Circuit Intermittent/Erratic
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.