Could you expand on that please? Always ready to learn something new!
Sure can. Your engine is an air pump. It sucks air in through the intake, and blows it out through the exhaust. Keeping the air flowing through that system is key, and not as straightforward as you might think. You don't - under any circumstances - want the airflow to stall. It can. And the reason it usually does is because of either an exhaust or intake system that is too large in diameter for the operating conditions the engine experiences.
Imagine an intake that is big enough for a 6.2L V8 on a 2400cc I4. It'll probably run fine at wide open throttle, but abruptly take your foot off the gas from WOT and it'll probably die. Why? Because the airflow in that oversized intake stalled and starved the engine for air. There's a sweet spot in which the diameters work best under most operating conditions. The stupid mistake that overly enthusiastic truck owners make is buying aftermarket intake and exhaust components that are optimized for race trucks that spend most of their operating lives at or near wide open throttle. But ask yourself these questions: "How much of my regular driving is spent with the pedal mashed to the floor?" and "How long would I keep my license if I drove that way?"
Automobile engineers know what they're doing. Yes, there are compromises. There have to be. But if your truck functions well the way you typically drive it, then making fundamental changes to the way it it runs will run the risk of proving unfortunate.