P047B

Exhaust Pressure Sensor B Circuit Range/Performance

Q: Is it safe to drive with P047B?

Usually yes, but the engine may cut power to protect the exhaust system. Drive gently and have it diagnosed soon, especially on a diesel.

Q: Can I just clear P047B?

It clears, but returns if the sensor, its tube, or the wiring is still producing an out-of-range signal.

Exhaust / emissions Generic OBD-II Medium

What it means

P047B means the second exhaust pressure sensor's signal is out of its expected range or inconsistent with other readings. This sensor supports EGR control and, on diesels, particulate filter regeneration. The usual cause is a clogged sensor tube or a failing sensor, and the engine may drop into reduced-power mode as a precaution.

Medium

Can I keep driving? Usually yes, though the engine may reduce power on diesels; drive gently and have it checked to protect the EGR/DPF system.

Real-world scan data

Seen in

120

scans in the past year

Found in

<0.1%

of scans

<0.1%

of scans that found faults

Appears alongside · share of P047B scans

P1525in 67.5% of scans

P2002in 65.0% of scans

P0574in 63.3% of scans

Figures reflect only diagnostic scans recorded through our own apps and tools. Cars are typically scanned because a symptom or warning light prompted it, so these counts describe our scan records — not the incidence of faults in any model, and not the quality, reliability, or safety of any vehicle. No comparison between manufacturers or models is implied. All trademarks belong to their respective owners; no affiliation or endorsement is implied.

Common symptoms

What you'll notice

Check-engine light on
Reduced power or limp mode (common on diesels)
Sluggish response under load
May fail an emissions/readiness test

Common causes

Most likely first

Faulty exhaust (back) pressure sensor B reading out of rangeLikely
Clogged or cracked sensor pressure tube to the exhaustCommon
Open or short in the sensor harnessCommon
Poor electrical connection at the sensor connectorLess often
Failed ECM (least common)Less often

How to diagnose & fix

Work through it in order

Read freeze-frame data and compare sensor B's live value against expected exhaust pressure.
Inspect the sensor's pressure tube/hose for soot blockage, cracks, or a loose fitting.
Check the connector and wiring for corrosion, a bent pin, or chafing.
Replace the exhaust pressure sensor B if it reads implausibly with a clear tube and good wiring.
Clear the code and re-test under load to confirm the repair.

FAQ

Quick answers

Is it safe to drive with P047B?+

Usually yes, but the engine may cut power to protect the exhaust system. Drive gently and have it diagnosed soon, especially on a diesel.

Can I just clear P047B?+

It clears, but returns if the sensor, its tube, or the wiring is still producing an out-of-range signal.

Read & clear P047B yourself

Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.

▶ Get it on Google Play

✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX