Hey im new to the Forum, i have a 97 GT pretty much stock, Just CAI and short throw shifter. So i noticed that when driving the car, if i try to floor it and gain quick acceleration my car starts to no shake but feel sluggish, I noticed that if i put in New Spark plugs the car will act as if nothing was wrong, great acceleration and smooth. but it only last a day or so, then its back to being sluggish. any idea on why? i do regular maintenance and dont beat on the car.