2002 Chevy Blazer MAF or VAF Service Code

2002 Chevy Blazer. Starts up fine cold, but when ran for 7-8 miles (when it gets warm) starts to bog out like not getting enough gas. The code MAF or VAF comes up. I can let vehicle sit for 1 minute-start it up & runs ok for another 7-8 miles. While vehicle was running & in park, popped the hood & pushed the idle arm to give her gas & she wants to bog out again & shut off. Changed fuel filter, but still does the same thing.