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'EVAP system small leak detected' 96 blazer

05-24-2004, 10:50 PM
96 Blazer 4.3L Vortec 90k miles
Couple weeks ago I got a check engine light, when I plugged it into Autotap it read:
H P0442 EVAP System small leak detected
There were two instances of this code, I erased them and it hasn't come back since, but I've been searching around and can't find any real information on what causes this, what sensor picks it up or anything like that, if anyone has any experience with this I'de appreciate any information you can give, thanks in advance.

05-25-2004, 12:14 AM
usually caused by a loose or damaged gas cap

05-25-2004, 02:31 AM

BigDaddy Royster
08-13-2004, 10:15 AM
OK, here's what I found out. If the gas cap does not fix the problem, you probably have a bad vent solenoid valve. The vent solenoid valve is in the engine compartment and must be replace. The part costs' about 30.00 bucks. Do not confuse this part with the fuel vent solenoid in the back of the truck. This will fix the P0442 error code and the service engine soon light. I hope this helps fellow GM owners..........

05-08-2006, 08:23 AM
Ok - go ahead and kill me for dragging up old - really old threads but does anyone know the the location of this "vent solenoid valve"? I can't find a listing in Advance or Autozone parts list.

05-08-2006, 07:36 PM
There are two solenoids in the Evap system. The canister purge solenoid is located on the intake manifold, on the passenger side next to the throttle body. Attached to the solenoid there is a 1/4" line that runs to a service port and from there to canister purge vent solenoid. There is also a two wire electrical connector on the solenoid. The canister purge vent solenoid is located in the driver side rear 1/4 panel, (behind the tire) next to the purge canister. There are three lines attached to it. One goes to the fuel tank, one to the canister, and one to the canister purge solenoid. There is also a two wire electrical connector on the vent solenoid.

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