My '97 GTS had the same problem. It stuck wide open on a county road and reached over 100mph. It stuck on a hard acceleration from a light and wouldn't come undone (I checked the floormat). At first I worried about the engine, everytime I engaged the clutch the RPM's went off the gauge. In case you're wondering, the brakes will not stop a Viper under full acceleration in low gear.
Once getting the car into 4th gear, the brakes started working. After a few more tense seconds, the brakes started failing! Fortunately I had already slowed the car enough to turn the key off without worry that I couldn't unlock the steering wheel to control the car.
I called Dodge and had it towed to the dealer. The problem was a cardboard tube left in the air intake line from the plant (supposedly). Apparently, as the intake valve would open/close, small pieces of the tube would be worn off and get stuck in the intake. This was finally fixed in 1999, after purchasing the car in 1997!
TRUE STORY. The engine was rumored to be one of the last ones built before the engine strike in early 1997...
Dodge was great, fixed the car and now it runs better than ever (gets more air than ever before without a cardboard tube blocking the intake)!