Code 71...Unless tank is full?

[Du6]

My 1990 4Runner v6 3.0 Auto 2WD will throw a code 71 about every 3 times I drive. But about a week ago, I filled the tank up and have been keeping it topped off whenever it gets around 3/4 of a tank and no codes. What would cause this behavior?
Thanks Very Much!
:thumb3:

(Code 71 is an EGR System issue)

 

[AZ4runnerPrerunner]

Is it the egr solenoid code?

 

[Du6]

Nothing I've seen says anything about solenoid(s).

 

[BucknutBob]

Could be an evap. system issue, as the level in the tank may affect the level of fumes coming from the tank to the charcoal canister. Just an idea--I can't say from personal experience, but the evap. system is directly affected from the gas tank.