P0496 Code: EVAP Flow During a Non-Purge Condition

The evaporative emissions control (EVAP) system is a major part of the vehicle. This part of your vehicle helps to collect the fuel vapors escaping from the fuel tank. It also assists in improving the engine performance. The powertrain control module (PCM) continuously observes the EVAP system performance. When your EVAP system experiences an issue with the purge flow, the PCM triggers the P0496 code. This article mainly explains the P0496 code symptoms, its causes, and how to fix it.

P0496 Code Definition

The P0496 code stands for “EVAP Flow During a Non-Purge Condition.”

What does the P0496 Code Mean?

The P0496 code indicates that the powertrain control module (PCM) of your vehicle detects that your evaporative emission (EVAP) system is experiencing an issue with purge flow.

The evaporative emission control (EVAP) system of your vehicle helps to seal the vehicle’s fuel system to stop the escaping of the fuel vapors from the fuel system and fuel tank to the environment.

The fuel vapors contain various hydrocarbons. When fuel vapors go into the atmosphere, hydrocarbons of the vapors generate smog after reacting with sunlight and air.

The purge flow is the amount of fuel vapor that enters the engine through the tubes. The fuel vapors generally depend on the amount of air entering the evaporative emission system from the intake vacuum.

The intake vacuum of your vehicle transfers the fuel vapors from the charcoal canister to the engine. When the fuel vapors enter the engine, they are combusted in the combustion chamber.

The PCM of your vehicle regulates the intake vacuum flow to the EVAP system. A canister is one of the major parts of the EVAP system that also collects fuel vapors from the gasoline tank. An intake vacuum normally directs air into the canister and allows fuel vapors to move via the purge valve when it opens.

Your PCM only triggers the P0496 trouble code when it detects high purge flow in the EVAP system. It indicates that more air enters the charcoal canister, which increases the delivery of fuel vapors to the engine.

Symptoms of the P0496 Code

The following are the most common symptoms of the P0496 code:

In most cases, the check engine light illumination may be the only symptom of the code P0496.
Your vehicle may also have rough running and other engine performance issues if fuel vapors are purged at the wrong time.
Hard to start the vehicle. The accumulation of fuel vapors in the engine compartment may cause problems starting the car.
Strong fuel odor especially when your car is parked or idling
Poor fuel economy (rare)
Catalytic converter damage (rare)

Causes of P0496 Code

The P0496 code is usually triggered due to one or more of the following causes:

Clogged charcoal canister
Missing or damaged gas cap
Clogged vapor canister
Bad purge valve
Bad EVAP pressure sensor
A leakage in the EVAP system hose
Plugged EVAP canister
Damaged or bad vent solenoid
A leak in the fuel tank
Damaged or corroded wiring to the EVAP system
Loose connections to the EVAP system
Clogged purge control valve
Leaking charcoal canister

How to Diagnose the P0496 Code

When your vehicle’s main computer triggers the P0496 engine code, it is very important to address it promptly. Follow the below-given steps to diagnose the P0496 code:

Firstly you need to ensure the presence of the P0496 code by using an OBD-II scan tool.
Collect the freeze data and analyze it to find the root cause of the problem. Clear the codes and perform a test drive. If the code returns, you need to inspect the whole system for a fault.
Check the electrical connections and wires of the EVAP system for damage or corrosion.
Properly inspect the purge control valve for a stuck open condition.
Check the fuel cap of your fuel tank for damage or leak.
Inspect the fuel tank for a leak or damage.
Inspect the EVAP pressure sensor for damage.
Inspect the vapor purge valve system for damage.
Examine the charcoal canister for a fault.
Visually inspect the EVAP pressure sensor for visible damage. Use a scan tool to test the performance of the EVAP pressure sensor.
Inspect the EVAP system for leaks. To check a leak, use an EVAP smoke machine leak checker to pressurize the EVAP system. If you observe a smoke leak from the EVAP system seals or hose, immediately repair the leaks.
After repairing the issues, clear the codes and perform a test drive.

Common P0496 Code Diagnosis Mistakes

Not properly inspecting all the parts of the evaporative emission system.
Replacing the purge control valve before inspecting the system for a leak.
Overlooking the inspection of the electrical wires and connections.
Replacing the EVAP pressure sensor or purge control valve before inspecting the electrical connections and wiring.
Not clearing the codes before diagnosing the system. It is necessary to clear the codes because sometimes, the PCM stores the fault code by mistake.

What repairs can fix the P0496 Code?

You need to repair or replace one or more of the following parts to fix the P0496 trouble code:

Replace the faulty fuel cap
Properly tight the fuel cap if it is loose
Fix the fuel tank leaks
Fix the vacuum hose leaks
Replace the faulty EVAP pressure sensor
Replace the bad purge control valve
Clean the clogged purge valve
Repair the damaged wirings to the EVAP system
Fix the leaky charcoal canister
Replace the bad charcoal canister
Replace the bad PCM

P0496 Code Repair Cost

To fix the P0496 code, you need one or more of the below-given repairs:

Parts	Cost
EVAP lines repair	$20 to $110
Gas cap replacement	$20 to $70
Fuel gauge sender replacement	$240 to $410
Purge valve replacement	$140 to $320
PCM replacement	$240 to $3000

How serious is the P0496 Code?

The P0496 code is not a serious trouble code. This code indicates a leak in the EVAP system. This code doesn’t generate many drivability issues. The only thing that could happen is the check engine light flashing. The existence of this code may increase exhaust emissions.

How to Prevent P0496 Code from Triggering?

To prevent the P0496 engine code from triggering, you need to apply the following control measures:

1) Tighten or Replace the Gas Cap

A damaged or leaky gas cap is a major cause of the P0496 code. Therefore, it is necessary to ensure that your gas cap is properly tightened after refueling.

If this cap is leaked or damaged, you need to replace it promptly.

2) Ensure Routine Maintenance

The regularly scheduled maintenance of your vehicle is very important if you want to achieve optimum performance by your EVAP system. Regular maintenance, including oil changes and tune-ups, ensures your vehicle is in good condition.

3) Maintain the EVAP System

Ensure proper maintenance and inspection of the EVAP system parts, such as canisters, valves, and hoses. You also need to address related problems promptly.

4) Avoid Overfilling

An overfilled fuel tank is also a major cause of triggering the P0496. When the fuel tank is overfilled, it may cause fuel to enter the EVAP system. Therefore, it is recommended not to overfill your tank while refueling.

5) Use Quality Fuel

The fuel plays a vital role in the performance of the EVAP system. Dirty or poor-quality gasoline may badly affect the performance of the EVAP system and cause the failure of different parts. Therefore, it is always recommended to use high-quality fuel.

6) Avoid Aggressive Driving

Harsh driving (i.e., hard braking and quick acceleration) can also create additional pressure in the fuel tank, affecting the performance of the EVAP system. Therefore, it is recommended to drive carefully.

FAQ Section

Can I drive with the P0496 Code?

Yes, you can drive with the P0496 code. This code doesn’t generate severe drivability issues. Mostly, your check engine light starts illuminating when PCM detects the P0496 code. This code indicates a problem with your EVAP system. Therefore, you should fix the issue as soon as possible. Your car may fail the emission test when your EVAP system goes bad.

How to fix the P0496 Ford?

To fix the P0496 Ford, you need to fix one or more below-given parts:

Replacing the leaked or faulty fuel cap
Replacing the bad charcoal canister
Tightening the fuel cap if it is loose
Fixing the fuel tank leaks
Fixing the vacuum hose leaks
Fixing the leaky charcoal canister
Replacing the faulty EVAP pressure sensor
Replacing the bad purge control valve
Cleaning of the clogged purge valve
Repairing the damaged wirings to the EVAP system

Can a loose gap cap cause the P0496 code?

Yes, a loose or damaged gas cap is one of the most common causes of the P0496 code. Ensure that your gas cap is properly tightened after refilling the fuel tank.

Can a bad EVAP pressure sensor cause P0496 code?

Yes, a bad EVAP pressure sensor may also trigger the P0496 code. The function of this sensor is to measure the fuel pressure within the fuel tank and send this data to the vehicle’s main computer.