My Scion has recently started a slight chug after he warms up. When I press the gas pedal in neutral it does a slight chug before it roars (never use to) but mainly when driving down the road 4th and 3rd gear (rpms enough ro be able to shift or cruise).
Thinking fuel filter (which means replace whole pump) or possibly a vacuum
/Air issue (does have the after market air intake system).
Any thoughts?