P0470 – Exhaust Pressure Sensor

P0470 is an OBD-II trouble code that points to a problem with your exhaust back pressure sensor circuit. You’ll often see it on turbocharged diesel trucks and some turbo gas engines, especially when there’s soot buildup or wiring issues. When this code sets, your engine computer can’t accurately read exhaust pressure, so it may protect itself by reducing power, changing shift points, or turning on the check engine light. Understanding what P0470 means, how it behaves, and how to fix it will save you time, money, and a lot of frustration.

What Does P0470 Mean?

P0470 stands for “Exhaust Pressure Sensor A Circuit Malfunction.” In plain terms, your ECU is not happy with the signal it’s getting from the exhaust back pressure (EBP) sensor. The voltage is out of the expected range, missing, or simply doesn’t match what the ECU calculates based on other sensors.

This code shows up most often on turbo diesels (Ford Powerstroke, Dodge/Ram Cummins, some Mercedes, VW, etc.), but it can appear on other vehicles that use an exhaust pressure sensor. It doesn’t always mean the sensor is bad; hoses, wiring, connectors, and exhaust restrictions can all trigger P0470.

Quick Reference

  • Code: P0470 – Exhaust Pressure Sensor A Circuit
  • Severity: Low to moderate, but can affect drivability and emissions
  • Common in: Turbo diesel trucks, especially Ford and Ram
  • Typical causes: Soot-clogged sensor tube, bad EBP sensor, wiring faults
  • Risk: Reduced power, poor fuel economy, potential DPF/EGR issues

Real-World Example / Field Notes

In the shop, I see P0470 most often on Ford Powerstroke diesels. A typical case: customer complains of low power, poor fuel economy, and a check engine light. Scan tool shows P0470 plus an EGR or DPF efficiency code. Live data reveals the exhaust back pressure sensor reading is stuck or lagging, especially during acceleration. Pulling the small metal or rubber tube to the sensor shows it completely packed with carbon. A quick cleaning of the tube and sensor port, clearing the code, and the truck is back to full power without needing expensive parts.

Symptoms of P0470

  • Check engine light on: The most obvious sign; P0470 is stored in the ECU memory.
  • Reduced power / limp mode: The ECU may limit boost and fuel to protect the engine and emissions system.
  • Poor fuel economy: Incorrect exhaust pressure data can cause inefficient fueling and timing.
  • Rough running or hesitation: You may feel hesitation or surging, especially under load or while towing.
  • Harsh or odd shifting: On some automatics, incorrect torque and load data can affect shift timing.
  • Regeneration issues on diesels: DPF regen may be delayed, too frequent, or incomplete.
  • Additional EGR/DPF codes: You may see related codes for EGR performance or DPF efficiency.

Common Causes of P0470

Most Common Causes

  • Soot-clogged EBP tube or port: Carbon buildup in the small tube from the exhaust manifold to the sensor is the number one cause on many diesels.
  • Failed exhaust back pressure sensor: Internal sensor failure, contamination, or drift causing incorrect voltage output.
  • Damaged wiring harness: Chafed, melted, or oil-soaked wires near the turbo or exhaust components causing shorts or open circuits.
  • Corroded or loose connector: Poor contact at the sensor plug leads to intermittent or incorrect readings.
  • Vacuum/pressure hose issues (where used): Cracked, soft, or disconnected hoses between the exhaust and sensor.

Less Common Causes

  • Exhaust restrictions: Severely clogged DPF or catalytic converter changing back pressure behavior beyond expected values.
  • Incorrect aftermarket parts: Non-OEM sensors or modified exhaust systems that don’t match ECU calibration.
  • ECU software glitches: Outdated engine control software misinterpreting sensor data, sometimes fixed with a reflash.
  • Internal ECU fault: Rare, but a failed driver circuit or internal reference voltage problem can trigger P0470.
  • Water intrusion: Moisture inside connectors or the sensor itself causing erratic readings, especially after heavy rain or washing.

Diagnosis: Step-by-Step Guide

You’ll want a basic tool set, a good scan tool (ideally with live data and Mode $06), a digital multimeter, and some carb or brake cleaner. On diesels, a small wire brush or pick is helpful for cleaning carbon from the EBP tube and port.

  1. Confirm the code and check for companions: Scan for P0470 and any related codes (EGR, DPF, boost). Note freeze frame data (RPM, load, speed) when the code set.
  2. Visual inspection: Locate the exhaust back pressure sensor and its tube. Look for melted wiring, rubbed harnesses, oil contamination, or broken connectors.
  3. Inspect and clean the EBP tube/port: Remove the tube from the exhaust manifold and sensor. Check for carbon blockage. Clean thoroughly with a pick and cleaner until it’s clear.
  4. Check sensor connector and pins: Unplug the sensor and inspect for corrosion, bent pins, or moisture. Repair or replace damaged connectors as needed.
  5. Test reference voltage and ground: With key on, use a multimeter to verify 5V reference and good ground at the sensor connector according to your wiring diagram.
  6. Check sensor signal voltage: Back-probe the signal wire. At key on/engine off, many sensors read close to barometric pressure (similar to MAP). Watch for a stable, reasonable voltage (often around 1–2V, varies by design).
  7. Monitor live data while driving: Watch exhaust back pressure vs. boost/MAP and engine load. The EBP reading should change smoothly with throttle. A flatline, spikes, or readings that don’t track load indicate a problem.
  8. Compare with known-good values or Mode $06: Some scan tools show test results for the EBP sensor. Look for failed or borderline tests. Compare readings to service information if available.
  9. Substitute a known-good sensor (if needed): If wiring, power, ground, and tube are all good, plug in a known-good or new sensor and recheck data.
  10. Clear codes and road test: After repairs, clear the DTCs and perform a drive cycle under similar conditions to confirm P0470 does not return.

Pro tip: On high-mileage diesels, treat EBP tube cleaning as regular maintenance. A partially clogged tube can cause intermittent P0470 long before it fully plugs up.

Possible Fixes & Repair Costs

Fixing P0470 can be straightforward once you pinpoint the cause. Common repairs include cleaning or replacing the exhaust back pressure tube, replacing the EBP sensor, repairing wiring, or addressing exhaust restrictions. Labor time is usually 0.5–2.0 hours depending on access and rust.

  • Clean EBP tube/port: Often $0–$150 (DIY vs. shop labor only).
  • Replace EBP sensor: Part $60–$250, plus 0.5–1.0 hour labor; total typically $150–$400.
  • Repair wiring/connector: $100–$350 depending on complexity and harness damage.
  • Fix exhaust restriction (DPF/cat): Can range from $400 to well over $2,000 on modern diesels.

Overall, most P0470 repairs land in the $150–$500 range when it’s just the sensor or tube. Costs climb if you need major exhaust or DPF work, or dealer-level diagnostics and ECU programming.

Can I Still Drive With P0470?

In many cases, you can still drive with P0470, especially if the only symptom is a check engine light. However, you may notice reduced power, poor fuel economy, or odd shifting. On some vehicles, the ECU will limit boost and fuel to protect the engine and emissions system, which can be dangerous when merging or towing. Short trips to the shop are usually fine, but you shouldn’t ignore this code for long, especially on a diesel with a DPF or heavy towing duty.

What Happens If You Ignore P0470?

Ignoring P0470 can lead to more frequent or failed DPF regenerations, increased soot buildup, and potential damage to the EGR and turbocharger over time. You may also pass unburned fuel and soot into the exhaust, shortening the life of expensive emissions components. Fuel economy and performance will likely continue to decline, and you may eventually end up in a more severe limp mode at the worst possible time.

Related Codes

  • P0474 – Exhaust Pressure Sensor Intermittent
  • P0473 – Exhaust Pressure Sensor High
  • P0472 – Exhaust Pressure Sensor Low
  • P0471 – Exhaust Pressure Sensor Range/Performance
  • P0469 – EVAP Purge Flow Sensor Circuit Intermittent
  • P0468 – EVAP Purge Flow Sensor Circuit High
  • P0467 – EVAP Purge Flow Sensor Circuit Low
  • P0466 – EVAP Purge Flow Sensor Circuit Range/Performance
  • P0465 – EVAP Purge Flow Sensor Circuit
  • P0464 – Fuel Level Sensor “A” Circuit Intermittent

Key Takeaways

  • P0470 means your ECU isn’t getting a proper signal from the exhaust back pressure sensor circuit.
  • On many diesels, a clogged EBP tube or port is more common than a bad sensor.
  • Symptoms range from a simple check engine light to reduced power, poor fuel economy, and DPF/EGR issues.
  • Diagnosis should include visual inspection, tube cleaning, wiring checks, and live data analysis.
  • Typical repair costs are moderate unless major exhaust or DPF components are involved.
  • Driving is usually possible, but you shouldn’t ignore the code, especially on a working or towing vehicle.

Vehicles Commonly Affected by P0470

P0470 is especially common on turbocharged diesel engines that rely heavily on exhaust pressure data. You’ll often see it on:

  • Ford: Powerstroke 6.0L, 6.4L, 6.7L in F-250, F-350, F-450 and larger Super Duty trucks.
  • Ram / Dodge: Cummins-powered 2500 and 3500 trucks with DPF and EGR systems.
  • Mercedes-Benz: CDI and Bluetec diesel engines in Sprinter vans and passenger cars.
  • Volkswagen / Audi: TDI engines where exhaust pressure is used for DPF and EGR control.
  • Other turbo diesels: Some GM Duramax and Asian-market diesels that use an EBP sensor.

Gasoline turbo engines that use exhaust pressure sensing can also set P0470, but it’s much more common in the diesel world due to soot and DPF systems.

FAQ

Can I clear P0470 and keep driving without fixing it?

You can clear the code, but if the underlying problem isn’t fixed, P0470 will almost always return. The ECU monitors the exhaust pressure signal continuously, so any ongoing issue with the sensor, tube, or wiring will trigger the code again, often within a single drive cycle.

Is P0470 always caused by a bad exhaust back pressure sensor?

No. While failed sensors are common, a clogged EBP tube or port and wiring issues are just as likely, especially on high-mileage diesels. That’s why you should always inspect and clean the tube and check power, ground, and signal wiring before throwing a new sensor at it.

How do I know if my exhaust back pressure tube is clogged?

Remove the tube from the exhaust manifold and try to blow through it or shine a light through it. If it’s heavily restricted or completely blocked with carbon, it needs to be cleaned or replaced. A clogged tube often causes slow or stuck sensor readings in live data.

Can P0470 cause my truck to go into limp mode?

Yes, it can. Many diesel ECUs rely on accurate exhaust pressure data for turbo, EGR, and DPF control. If the reading is missing or clearly wrong, the ECU may reduce power, limit boost, and change shift behavior to protect the engine and emissions system.

Do I need a dealer scan tool to diagnose P0470?

Not necessarily. A good aftermarket scan tool that shows live data, freeze frame, and Mode $06 is usually enough for most P0470 problems. However, for complex cases involving ECU updates, advanced DPF diagnostics, or conflicting codes, a dealer or specialist shop with factory-level equipment can save time and guesswork.