So I've got a 96 GT with the 4.6 and a 5 speed. I've owned it for about 3 years now and have dumped thousands into it, mostly mods and basic maintenance though. Ever since I've had it, it's had a weird idle and the revs take FOREVER to drop. Sometimes it idles perfectly when warmed up, other times it stays a few hundred RPM's higher than it should. It just seems like the computer is detecting the throttle hanging open longer than it should. I have checked the linkage and adjusted the set screw and what not, to no avail. The ECU isn't throwing any codes either, which is odd. I've also replaced the plugs, plug wires, coils, cat converter, ALL o2 sensors, TPS, IAC valve, MAF sensor, air charge sensor, throttle body, k&n cold air intake, and the PCV valve. After all of this, the revs still don't sound right. I am at a loss now, and before I spend a crazy amount of money on more parts, I figured I'd get some opinions. The motor also seems to bog down/lose power after about 4200-4500 rpm's. It pulls hard up until then, but goes absolutely flat right after. Maybe that is also a symptom of what ever is failing and causing the revs to drop slowly? Let me know what you think!