P0407 Code Meaning and Next Steps

First checks take 10 to 20 minutes for the first checks. No special tools are usually needed for the first checks.

Can you keep driving?

Stop driving if any of these apply

!The engine starts running much worse, stalls, or the warning light flashes.
!The vehicle begins to overheat, knock, or lose power sharply while the code is active.

If the light is steady and the vehicle still drives normally: Often yes for a short time, but it should not be ignored.

What to check first

Step-by-step checks

1
Free - no tools
Let the engine cool before checking the valve and wiring
2
Free - no tools
Inspect the sensor connector and harness for corrosion, looseness, or a pinched wire
3
Basic tool needed
If the valve moves, see whether the sensor signal changes smoothly across the travel range
4
Basic tool needed
Check whether the code appeared after EGR work or intake service
5
Basic tool needed
If scan data is available, compare commanded movement with the sensor response

If the code returns

-If the signal stays low on a known-good circuit, the sensor moves higher on the list.
-If moving the harness changes the reading, wiring repair comes before a new valve.
-If the code returns after replacement, verify the reference and ground side again.

Background

What this code means

P0407 is a generic OBD-II code for a low-input EGR sensor B circuit fault.

That usually means the ECU is seeing a signal lower than expected on the second EGR feedback channel or circuit.

Diagnosis

Common causes

Most common

Shorted EGR sensor B circuit

A short to ground can pull the reading low.

Common

Failed EGR sensor B

The sensor may no longer report a believable signal.

Common

Connector or harness issue

A poor connection can create the same low-input fault.

Possible

Carbon-stuck valve

If the valve cannot move properly, the sensor may look wrong.

Avoid these mistakes

What not to do

xDo not replace the sensor or valve first if there is obvious wiring, connector, or vacuum damage.
xDo not ignore drivability changes just because the code sounds like an emissions fault.

Parts

Parts that may need replacing

PartTypical costNotes

EGR sensor or valve assembly$80-$300Relevant when the feedback circuit remains low.

Connector repair$15-$120Useful if the plug or pins are damaged.

EGR gasket or cleaning supplies$20-$100Worth checking if carbon buildup is part of the issue.

Related OBD codes

P0403

P0403 usually means the EGR control circuit has a malfunction.

P0404

P0404 usually means the EGR system is out of range or performing poorly.

P0405

P0405 usually means the EGR position sensor is reading too low.

P0406

P0406 usually means the EGR position sensor is reading too high.

Source notes

Generic OBD-II (SAE J1979 / ISO 15031-5). P0407 was expanded around common low-input EGR sensor B faults, especially shorts, wiring issues, and carbon-stuck valves.

This guide is written as a generic multi-make reference, so bulletin history, sensor locations, and repair order can still change by manufacturer and engine family.

This is generic OBD-II guidance and should not override vehicle-specific service information. Exact diagnosis and repair steps vary by make, engine family, and model year.

Last reviewed: 2026-04-10

Reference: Open reference

P0407 - P0407 Usually Means the Egr Sensor B Circuit Is Reading Too Low