P1EFA Mercedes-benz 170 Diagnostic Trouble Code

P1EFA Mercedes-benz 170 code definition:
P1EFA is a kind of OBD-II Diagnostic P-Powertrain Diagnostic Trouble Code for Mercedes-benz 170.

P1EFA Mercedes-benz 170 or the Evaporative Emission Control System Incorrect Purge Flow is the set whenever the computer sees that there is a problem with the flow coming from the purge valve or the purge flow is not enough within the EVAP system. If the car doesn't start, they will proceed by testing the voltage at the fuel pump connector and see if the fuel pump relay, fuse, and PCM circuitry should be inspected.

Symptoms

Symptoms of a P1EFA Mercedes-benz 170 diagnostic trouble code may include:

Faulty PCM
The light may stay on or light intermittently as the DPF regenerates. The engine will be sluggish on acceleration.
Poor acceleration
Reduction in engine performance, especially at low RPM levels

Possible Causes :

Dirty air cleaner element Damaged DPF
A plugged converter will cause of host of driveability problems as well as set this code. A severely plugged converter will result in the inability to increase rpm when under load. Look for a code such as P0421 -- catalytic converter efficiency below threshold if the converter indicating a faulty converter.
A large air leak at or near the number one oxygen sensor would also cause a lean mixture.

Common Misdiagnoses

TP Sensor Learn Not Complete Problem
Low Coolant Circuit Problem
Cruise Control System - Vehicle Accel Too High Problem
TFP Valve Position Switch-Drive Without Drive Ratio Problem
Problem

Repair Processes :

If the scan tool has that capability, and the scan tool can operate the IMRC valves, then the problem is either resolved and a simple code clearing is all that's left or a new PCM would be called for. Look for damage to the tank indicating impact that may have damaged the fuel pump or sender.

Process Tips

Diagnostic trouble code P1EFA Mercedes-benz 170 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 P1EFA Mercedes-benz 170.

Fortunately, P1EFA Mercedes-benz 170 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.