P0456 Diagnostic Trouble Code

P0456 is a kind of OBD-II Diagnostic P-Powertrain Diagnostic Trouble Code.

It is considered generic because it applies to all makes and models of vehicles, although specific repair steps may be different depending on your car model.

Symptoms

Symptoms of a P0456 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)

Repair Processes :

Look at the plug wires to make sure they are not burnt or laying on the exhaust. Look for missing ground strap or a rusty ground where the fuel tank is grounded to the frame. Check for damage to the wiring harness connector. Look for rubbing, scraping, bare wires, worn spots or melted plastic connectors. Pull the connectors apart and carefully look at the terminals (the metal parts) inside the connectors.

Process Tips

Diagnostic trouble code P0456 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 P0456.

Fortunately, P0456 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

P0456 Trouble Code For Specific Cars

P0456 Td Cars Td2000 Misfire Detected - Rough Road Data Not Available
P0456 Db Coach HO2S Heater Control Circuit Low (Bank 2 Sensor 1)
P0456 Skoda 110 IPR Circuit Failure
P0456 Isuzu Impulse
P0456 Plymouth Laser Evaporative Emission Control System Vent Control Circuit Malfunction
P0456 Peugeot 5008 Ii EIC Switch-2 Assembly Circuit Failure
P0456 Ferrari 225 Injector High Sides Shorted Together