The prevailing pressure in the tank forces hydrocarbon gases into the activated charcoal canister. The molecules of fuel are trapped in the canister material. The tank ventilation valve is activated by the engine control unit when vacuum is present in the intake manifold. The vacuum and regenerated air work together in order to force the canister of fuel molecules and reintroduce them to the combustion process.

Have you ever had the. Following fault errors when you run a scan on your car.

P0441 - evaporative emission control system incorrect purge flow

P0442- evaporative emission control system leak detected (small leak)

P0446- evaporative emission control system vent control malfunction.

The above fault error also contributes to high fuel consumption. Car owners have always wanted to know why their cars consume so much fuel. Here is just a tip. Gas accumulated from fuel stored in tank can be lost through a leak from the canister box or its vacuum lines. I would be uploading a life pix of some of these items that comprises the tank ventilation system.

From my experience on the field most car owners over fill their fuel tank to the point where fuel Starts to gush out of the fuel tank despite the check valves actually playing its function stating when to stop adding more fuel when refilling the tank. The adverse effect of this results to a "bad charcoal canister"

A bad charcoal canister box taken out of a Lexus Rx330 2005

Another praticising culture is running your engine and at the same time refueling your cars. That's not a good practice for a modern day vehicle. This can also damage the canister box

Please tell them.
I'm tired of seeing people rocking their cars sideways so that more petrol can enter the tank. Na groundnut bottle?

DaimlerBen:
Please tell them.
I'm tired of seeing people rocking their cars so that more petrol can enter the tank. Na groundnut bottle?

Have seen to an extent where car owner insists he needs more and more fuel in. Groundnut bottle

DaimlerBen:
Please tell them.
I'm tired of seeing people rocking their cars so that more petrol can enter the tank. Na groundnut bottle?

Hahaha... That one sef dey.

I have this error code P0441.

I don't fill up to the brim tho. Half tank is what I do. I've changed fuel pump though I got to know its not probably the culprit since its still pulling same code

Its a 2003 Toyota Avalon.

What else can be the culprit, pls?

DreCharles:
I have this error code P0441.

I don't fill up to the brim tho. Half tank is what I do. I've changed fuel pump though I got to know its not probably the culprit since its still pulling same code

Its a 2003 Toyota Avalon.

What else can be the culprit, pls?

A simple start from your fuel tank cover could just be a culprit. Pull out your tank cover inspect the rubber seal for breakage. If all is fine you need to check for leaks around vacuum line. If no leak test your purge control valve solenoid (vsv- vacuum switching valve) and make sure it works fine.

Other trouble areas could be

1) charcoal canister

2) cracked fuel tank

3) vapour pressure sensor which is situated right on top of the fuel tank used to measure vapour pressure from fuel. If you cannot access right from underneath your sit then your tank needs to come down. Who never can tell rodents might just have fisted on its wiring

In a case where you do not see a visible leak,.a.smoke detector machine can be used to trace leak.

I hope this helps. A pix of a.charcoal canister has been earlier uploaded. Yours should be situated close to underneath your fuel tank

Pix of a vacuum switching valve (purge control valve solenoid). As shown on a Toyota Highlander 2001 (1mz-FE). We have the VSV1 and VSV2

Vacuum hose with a service port connected down to the canister box through which gas is being transported to inlet manifold plenum. The service port is a trouble shoot area that has a valve inside through which your smoke detecting machine can be plugged

A typical caricature diagram of an evaporative emission control system.
Source: www.AA1car.com

mayor2013:
A typical caricature diagram of an evaporative emission control system.
Source: www.AA1car.com

more pls

Been having code p1450 EVAP control system fault on my 2001 Mazda millenia for a while now. Tried all the necessary (Purge valve is fine, filler cap is fine e.t.c), but I still get the code. Any solution?

seunoresco:
Been having code p1450 EVAP control system fault on my 2001 Mazda millenia for a while now. Tried all the necessary (Purge valve is fine, filler cap is fine e.t.c), but I still get the code. Any solution?

You could have a leak along the evap line. You need to test where leak is coming from. This leads to escape of gas hence the fault error. Also check your canister box

I have these codes, I don't know the mechanic to contact that can understand this. What do I do? The mechanics in my area are just trial by error guys.