Keep getting P0440 code. on 2001 Chevrolet Blazer

I keep getting the 440 code. had vapor lines replaced after smoke test. light came back 3 days later. had vent valve replaced, light still came back on 2 days later. i fill up, i turn gas cap like 3 times to make sure it sealed. Please help!

by in Plainfield, CT on April 13, 2013
1 answer
ANSWER by on April 14, 2013
you need another smoke test its probly in the fill neck
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I got 440 code, had a smoke test done, repalced vapor lines. light came back on 3 days later with same p0440 code. had vent valve replaced. light came back on 2 days later. same code again... pleas...