OBD Guide

P28F9

Exhaust Pressure Too Low Bank 1

P28F9 is an OBD-II diagnostic trouble code meaning: Exhaust Pressure Too Low Bank 1. Common causes: leak in exhaust system, malfunction of the exhaust gas pressure sensor. Estimated repair cost: $17–167.

Severity
⚠️ Medium
Can you drive?
Yes, but get it checked soon
Approx. repair cost
$17–167 (est.)

Symptoms

  • Reduced engine power
  • Increased fuel consumption
  • Check Engine Light Is On
  • Unusual noises from the exhaust system
  • Dips during acceleration

Causes

  • Leak in exhaust system
  • Malfunction of the exhaust gas pressure sensor
  • Problems with the turbocharger (if installed)
  • Clogged or damaged catalytic converter
  • Open or short circuit in the sensor circuit

How to Fix

  1. Visual inspection of the exhaust system for leaks
  2. Checking the exhaust gas pressure sensor
  3. Turbocharger diagnostics (if equipped)
  4. Checking the condition of the catalytic converter
  5. Testing the sensor electrical circuit

Related codes

Error P28F9 by Vehicle Brand

FAQ

What does the P28F9 code mean?

P28F9 is an OBD-II diagnostic trouble code that indicates: Exhaust Pressure Too Low Bank 1

What causes a P28F9 error code?

The most common causes of P28F9 include: Leak in exhaust system; Malfunction of the exhaust gas pressure sensor; Problems with the turbocharger (if installed); Clogged or damaged catalytic converter.

How do I fix a P28F9 diagnostic trouble code?

To fix P28F9: Visual inspection of the exhaust system for leaks. Checking the exhaust gas pressure sensor. Turbocharger diagnostics (if equipped). For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P28F9?

Yes, but get it checked soon

How much does it cost to fix P28F9?

The estimated repair cost for P28F9 is $17–167. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat