P041B
EGR Temperature Sensor B Circuit Range/Performance
Emissions (EGR)
Generic OBD-II
Medium
What it means
P041B means the "B" EGR temperature sensor is reporting a value the ECM considers implausible — it may respond too slowly, stick, or drift out of range rather than tracking real exhaust temperature. It's an emissions monitoring fault: the car usually drives normally, but the sensor or its wiring needs attention and it can fail an emissions test.
Medium
Can I keep driving? Safe to drive short-term — this is an emissions monitoring fault; the car usually drives normally but can fail an emissions test.
Common symptoms
What you'll notice
- Check-engine light on
- Often no noticeable change in how the car drives
- Failed emissions test
- Occasional rough EGR operation
Common causes
Most likely first
- EGR temperature sensor B reading implausibly (slow, stuck, or out of range)Likely
- Damaged wiring or high resistance in the sensor circuitCommon
- Loose or corroded connector at the sensorCommon
- Carbon build-up on the sensor slowing its responseLess often
- ECM fault (rare — verify the sensor and wiring first)Less often
How to diagnose & fix
Work through it in order
- Scan and read freeze-frame data to confirm the fault is the EGR temperature sensor B circuit.
- Compare the sensor's reported temperature to actual conditions — it should track engine and EGR warm-up.
- Inspect the connector and wiring for corrosion, chafing, or high resistance.
- Remove the sensor and check the tip for carbon fouling that dulls its response.
- Replace the EGR temperature sensor if it reads implausibly with good wiring. Clear and re-test.
FAQ
Quick answers
Is it safe to drive with P041B?+
Yes, short-term — it's an emissions monitoring fault rather than a driveability risk. Fix it before an emissions test or extended driving.
Can I just clear P041B?+
It comes back once the ECM re-evaluates the sensor's performance. The sensor or wiring has to be addressed.
Related codes
Often seen with P041B
Read & clear P041B 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