P046F
EGR Sensor B Circuit Intermittent/Erratic
Emissions / EGR
Generic OBD-II
Medium
What it means
P046F means the EGR position sensor "B" signal is dropping out or jumping around instead of reading steadily. Because the fault is intermittent, the most common cause is a wiring or connector problem rather than the sensor itself. The engine usually runs, but an unstable EGR reading can cause occasional rough running or pinging until it is repaired.
Medium
Can I keep driving? Usually drivable, but an erratic EGR signal can cause occasional rough running or pinging, so fix it before it becomes constant.
Common symptoms
What you'll notice
- Check-engine light on
- Occasional rough idle or hesitation
- Pinging or knocking under load (intermittent)
- May fail an emissions test
Common causes
Most likely first
- Intermittent wiring fault — chafed, loose, or broken conductor in the EGR sensor B circuitLikely
- Corroded or poorly seated sensor connectorCommon
- Faulty EGR position sensor BCommon
- Carbon fouling affecting the sensor's readingLess often
How to diagnose & fix
Work through it in order
- Wiggle-test the EGR sensor B wiring and connector while watching for the signal to drop out.
- Inspect the connector for corrosion, spread pins, or moisture.
- Check the sensor's ground and reference voltage.
- Replace the EGR position sensor if the signal is erratic with good wiring, then clear and re-test.
FAQ
Quick answers
Is it safe to drive with P046F?+
Short trips are usually fine, but an erratic EGR signal can cause pinging under load, which stresses the engine. Have it diagnosed soon.
Can I just clear P046F?+
An intermittent code may stay away briefly, but it returns until the wiring, connector, or sensor is repaired.
Related codes
Often seen with P046F
Read & clear P046F yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX