OBD Guide

P03E4

Cylinder 8 Combustion Performance

P03E4 is an OBD-II diagnostic trouble code meaning: Cylinder 8 Combustion Performance. Common causes: spark plug fault, problems with the ignition coil. Estimated repair cost: $33–167.

Severity
⚠️ Medium
Can you drive?
Limited driving only, diagnose soon
Approx. repair cost
$33–167 (est.)

Symptoms

  • Unstable engine idling
  • Reduced power and dynamics
  • Increased fuel consumption
  • Vibrations during engine operation

Causes

  • Spark plug fault
  • Problems with the ignition coil
  • Dirty or faulty injector
  • Low cylinder compression
  • Air leak in the intake manifold
  • Knock sensor malfunction

How to Fix

  1. Check the condition of the spark plug in cylinder 8
  2. Test the ignition coil
  3. Clean or replace fuel injector
  4. Measure the compression in the cylinder
  5. Check the intake manifold for leaks
  6. Diagnose the knock sensor

Related codes

Error P03E4 by Vehicle Brand

FAQ

What does the P03E4 code mean?

P03E4 is an OBD-II diagnostic trouble code that indicates: Cylinder 8 Combustion Performance

What causes a P03E4 error code?

The most common causes of P03E4 include: Spark plug fault; Problems with the ignition coil; Dirty or faulty injector; Low cylinder compression.

How do I fix a P03E4 diagnostic trouble code?

To fix P03E4: Check the condition of the spark plug in cylinder 8. Test the ignition coil. Clean or replace fuel injector. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P03E4?

Limited driving only, diagnose soon

How much does it cost to fix P03E4?

The estimated repair cost for P03E4 is $33–167. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat