evap control

[avsfans33]

First time on...new owner. I have an 03 discovery and recently got an p0441 code and p1171 and p1174 Pending. Can I get help as to where to start looking for problems. Seems to be a variety of things to could be potential. Whats the easiet place to start.

Thanks for the help
avfans33

[Disco Mike]

How many miles on your 03? What octane gas are you running?
Mike

[avsfans33]

I bought is with 42,000 and now I have 53,000. I am learning that LR can be sensitive and I usually put mid to premium in now. ( I have put in cheap stuff, but not recently) Interestingly, I cleared the code and drove in the mountains for the weekend and it did not come on until I got back down close to sea level.

[Elemental]

The reason the code came back after you cleared it is because something is wrong. The computer is looking for a rich condition at purging of the canister. MOST of the time a replacement valve clears this up.

I have heard, but have never done it.... That a Hyundai purge valve bolts right in. MUCH cheaper then the same aprt with a green oval stamped on it.

[avsfans33]

Is the vapor canister filter the same as what you are talking about?

[Elemental]

No, The evap purge valve is different. First, call you dealer and make sure recall RB167 doesnt apply to your truck, if it does....FREEBIE!


Here is a Briefing of what is going on.

The evaporative emission monitoring system used for the Discovery 2001MY onwards permits the detection of leaks with a diameter of 0.020 inches or greater .
This is achieved by means of a pressure test of the system. This is performed by the DMTL, which is an electrically operated pump fitted to the atmospheric air intake of the EVAP Canister.
From the 2002MY this unit contains an electric heater to prevent condensate formation.
The test proceeds in 2 stages:
Reference Leak Measurement - The pump operates against the reference restriction within the DMTL. The ECM measures the current consumption of the pump motor during this phase.

Leak Measurement (see diagram) - The solenoid in the DMTL is operated in order to shut off normal purge airflow into the EVAP Canister. The pump can now pressurise the fuel tank and vapour handling system. The ECM again measures the current consumed by the pump motor and by comparing this with the reference current, determines if a leak is present or not. A high current indicates tight system and a low current indicates a leaking system.

[avsfans33]

Thanks for the info... I will start with that....

[Rovin4life]

needs a purge valve, that will take care of the 0441, but the air leaks seems like something is loose check all air hose and pcv hose connections for looseness or leaks.