OBD Guide

P03A4

Cylinder 2 Pressure Too Low

P03A4 is an OBD-II diagnostic trouble code meaning: Cylinder 2 Pressure Too Low. Common causes: worn or damaged piston rings, valve burnout or deformation. Estimated repair cost: $56–333.

Severity
⚠️ Medium
Can you drive?
Limited driving only, diagnose soon
Approx. repair cost
$56–333 (est.)

Symptoms

  • The engine hesitates or runs rough
  • Power reduction
  • Increased fuel consumption
  • Vibration at idle

Causes

  • Worn or damaged piston rings
  • Valve burnout or deformation
  • Leaking cylinder head gasket
  • Faulty injector or fuel pump
  • Problems with the ignition system (plugs, coils)

How to Fix

  1. Check compression in cylinders
  2. Inspect spark plugs and coils
  3. Check the condition of the injectors
  4. Diagnose the fuel pump and fuel rail pressure
  5. Inspect the valves and piston group
  6. Replace damaged parts

Related codes

Error P03A4 by Vehicle Brand

FAQ

What does the P03A4 code mean?

P03A4 is an OBD-II diagnostic trouble code that indicates: Cylinder 2 Pressure Too Low

What causes a P03A4 error code?

The most common causes of P03A4 include: Worn or damaged piston rings; Valve burnout or deformation; Leaking cylinder head gasket; Faulty injector or fuel pump.

How do I fix a P03A4 diagnostic trouble code?

To fix P03A4: Check compression in cylinders. Inspect spark plugs and coils. Check the condition of the injectors. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P03A4?

Limited driving only, diagnose soon

How much does it cost to fix P03A4?

The estimated repair cost for P03A4 is $56–333. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat