B1238 Marcos 3-litre Diagnostic Trouble Code

B1238 Marcos 3-litre code definition:
B1238 is a kind of OBD-II Diagnostic B-Body Diagnostic Trouble Code for Marcos 3-litre.

B1238 Marcos 3-litre is a DTC or a diagnostic trouble code. It is a check engine light code which indicates that the catalyst's system efficiency is less than the required threshold. In simple terms, it means that more pollution is added into the air than what was supposed to be because of your car. Other symptoms that may indicate this problem are when the Check Engine Light illuminates and when there is a visible lack of engine power.

Symptoms

Symptoms of a B1238 Marcos 3-litre diagnostic trouble code may include:

Reduction in engine performance, especially at low RPM levels
Vacuum leak on the engine
Diminished fuel efficiency
The engine oil will exhibit dilution from the ECUs attempts to increase engine temperature. Some vehicles advance the fuel injection timing slightly after top center to afterburn a small amount of fuel to increase exhaust temperatures. Some of this fuel enters the crankcase. When the ECU determines the necessity to regenerate the DPF, the service life of the oil be shortened significantly

Possible Causes :

A large vacuum leak would cause a massive amount of un-metered air to enter the intake manifold resulting in an overly lean mixture.
Faulty IMRC actuator/sensor
Dirty air cleaner element Damaged DPF

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 :

If the engine displays a miss and there wasn't a code, determine which cylinder is misfiring. If the exhaust manifold is visible, spay or pour a small amount of water on each cylinder exhaust port. Water will evaporate immediately on good cylinders and slowly on the missing cylinder. If this can't be accomplished pull the plugs and check the condition. You might continue by connecting the scanner to the vehicle diagnostic connector and retrieving all stored codes and freeze frame data. Look for damage to the tank indicating impact that may have damaged the fuel pump or sender.

Process Tips

Diagnostic trouble code B1238 Marcos 3-litre 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 B1238 Marcos 3-litre.

Fortunately, B1238 Marcos 3-litre is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.