B0744 Subaru Forester 2 Diagnostic Trouble Code

B0744 Subaru Forester 2 code definition:
B0744 is a kind of OBD-II Diagnostic B-Body Diagnostic Trouble Code for Subaru Forester 2.

B0744 Subaru Forester 2 is defined as Cylinder 3 Injector Circuit Malfunction. This code means the PCM (powertrain control module, also known as ECM or engine control) has detected a problem in the injector or its wiring, or in injector circuit for cylinder 3. This is because the barometric pressure sensor is part of the MAF sensor. Sometimes, the MAF's sensing wire can accumulate and get covered with dirt, dust and/or oil residue, which can also lead to the error code.

Symptoms

Symptoms of a B0744 Subaru Forester 2 diagnostic trouble code may include:

Rich or lean exhaust
Fuel pressure too low
Engine surge
Hesitation upon acceleration

Possible Causes :

Some aftermarket accessories and performance modifications
A faulty oxygen sensor. This will set a code in itself, however, a faulty oxygen sensor does not automatically condemn the sensor. The code just means that the sensor signal was not within specifications. An air leak or any of the above will cause an erroneous signal. There is a multitude of O2 codes relating to O2 performance which gives a clue to the problematic area.
Faulty IMRC actuator relay (if equipped)

Common Misdiagnoses

Crankshaft Position Sensor Circuit Performance Problem
TP Sensor Learn Not Complete Problem
Low Coolant Circuit Problem
Cruise Control System - Vehicle Accel Too High Problem
Kick-Down Switch Failed Short Problem

Repair Processes :

Replace the oxygen sensor that is downstream from the catalytic converter on the side of the engine that does not contain cylinder #1. Also, if a oxygen sensor code stating "heater circuit malfunction" the sensor has most probably failed. With the valve disconnected, the red voltmeter lead should be attached to the IMRC valve power wire and the black voltmeter lead connected to ground. You might continue by connecting the scanner to the vehicle diagnostic connector and retrieving all stored codes and freeze frame data.

Process Tips

Diagnostic trouble code B0744 Subaru Forester 2 is not difficult to diagnose and repair. Thus, it always pays to have a qualified technician to look after your vehicle should this error code arise.

Diagnosing this code requires the engine to be in good running shape, without unmetered air entering the engine. If other codes that relates to misfiring condition, lean running or air entering the engine is present, then you must first fix those error codes before B0744 Subaru Forester 2.

Fortunately, B0744 Subaru Forester 2 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.