OBD Guide

P1284

Air Fuel Ratio Sensor 1 Rich Shift Monitoring Bank 2

P1284 is an OBD-II diagnostic trouble code meaning: Air Fuel Ratio Sensor 1 Rich Shift Monitoring Bank 2. Common causes: air-fuel ratio (afr) sensor malfunction, fuel leak in injectors. Estimated repair cost: $22–89.

Severity
⚠️ Medium
Can you drive?
Limited driving only, diagnose soon
Approx. repair cost
$22–89 (est.)

Symptoms

  • Increased fuel consumption
  • Reduced engine power
  • Black smoke from the exhaust pipe
  • Unstable engine idling
  • Gasoline smell from exhaust

Causes

  • Air-fuel ratio (AFR) sensor malfunction
  • Fuel leak in injectors
  • Increased pressure in the fuel rail
  • Contamination or malfunction of the air flow sensor
  • Exhaust gas recirculation (EGR) system malfunction

How to Fix

  1. Check the operation of the bank 2 AFR sensor
  2. Diagnosis of fuel injectors for leaks
  3. Check the pressure in the fuel rail
  4. Clean or replace the mass air flow sensor if necessary
  5. Check the EGR system for correct operation

Related codes

Error P1284 by Vehicle Brand

FAQ

What does the P1284 code mean?

P1284 is an OBD-II diagnostic trouble code that indicates: Air Fuel Ratio Sensor 1 Rich Shift Monitoring Bank 2

What causes a P1284 error code?

The most common causes of P1284 include: Air-fuel ratio (AFR) sensor malfunction; Fuel leak in injectors; Increased pressure in the fuel rail; Contamination or malfunction of the air flow sensor.

How do I fix a P1284 diagnostic trouble code?

To fix P1284: Check the operation of the bank 2 AFR sensor. Diagnosis of fuel injectors for leaks. Check the pressure in the fuel rail. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P1284?

Limited driving only, diagnose soon

How much does it cost to fix P1284?

The estimated repair cost for P1284 is $22–89. Actual cost depends on your vehicle, location, and labor rates.

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