Hello i have a 99 blazer 4 door and my service engine light came on, so i had run of my buddies run a scan tool on it and it said P0440 evap emissions control failure. I have no idea what that means... has any one had this code pop up before? thank you

 

This typically points to a improperly tightened gas cap, faulty gas cap, or over filled gas tank. Did you recently fill up with fuel? When you tighten your gas cap, do you tighten until you hear it click 3 or more times?

 

I check the gas cap as soon asthe light came on i had that happen b4... I have not filled up with gas for a while, but i noticed when that light came on it sure felt like i was using up more gas.

 

The evaporative leak detection diagnostic strategy is based on applying a vacuum to the EVAP system and monitoring the vacuum decay rate. The VCM monitors the vacuum level via the fuel tank pressure sensor input. At an appropriate time, the EVAP purge solenoid and the EVAP vent solenoid turn ON, allowing the engine vacuum to draw a small vacuum on the entire evaporative emission system. If a sufficient vacuum level cannot be achieved, a large leak or an EVAP system malfunction is indicated. The following conditions can cause this problem:
[*]A disconnected or malfunctioning fuel tank pressure sensor[*]A missing, malfunctioning, improperly installed, or loose fuel cap[*]A disconnected, damaged, pinched, or blocked EVAP purge line[*]A disconnected or damaged EVAP vent hose[*]A disconnected, damaged, pinched, or blocked fuel tank vapor line[*]A disconnected or malfunctioning EVAP purge solenoid[*]A disconnected or malfunctioning EVAP vent solenoid[*]An open ignition feed circuit to the EVAP vent or purge solenoid[*]A damaged EVAP canister[*]A leaking fuel sender assembly O-ring[*]A leaking fuel tank or fuel filler neck [/ul]
Any of the above conditions can set a DTC P0440.

 

Does anybody know how I can get the Purge/Vent Solenoid? Do you think this will help? This is the same Damn code I've been getting every time.

 

The vent/purge solenoid is available at your favorite autoparts store. The location depends on whether you have a 2dr or a 4dr. I can't remember the exact location of the 2dr vent/purge solenoid, but on a 4dr, just drop the spare tire if you have it underneith and it'll be in the middle of the crossmember directly behind the rear axle. It'll have one large vacuum line and an electrical connector.

 

Kyle,

I went to Autozone, Pepboys and Advanced Auto. None of them had them in stock. Not sure if they need to special order it.

 

Hmm Could have sworn that they were available in the aftermarket. But anyway, its ACDELCO Part # 214633. Shouldn't be more than $20 from your local dealer... That is the purge valve. The purge solenoid is on the engine, but this is rarely the source of a P0440 code.

 

My truck is running good. No Check Engine Light in about "3 weeks"

 

my 97 expericence the same problem after i purchased it.. I didnt realized the pump was changed also. I Changed both the selenoids on the engine and under the spare tire... with no luck.. replaced the fuel pressure sensor on the fuel pump sending unit without dropping the tank and still no luck and of course the gas cap.. I spent last weekend dropping the tank and low and behold the vent valve was broke off at the vacuum line fitting. Since i replaced all the sensors myself i know i stll saved money . Dealer wanted $400 to drop the tank..and replace the valve... $20 for that little problem part at the dealer and about half a day labor but well worth it...Go to rockauto.com... they have the illustrations that will help you.