I have a 2000 455-D that will start and run OK, will idle at low or high throttle for as long as I want, but as soon as I press the forward drive pedal, it stalls out. This is a dead shut off where the glow plug light comes back on and the engine will recover if I pull my foot off fast enough. My local TORO shop mechanic thought it might be safety switch related and suggested that route. I located the seat switch and it appears to be OK. I unplugged it and jumpered out the connector and there was no difference, it still stalled. Any advice? As a side note; I have owned this unit for 5 years and use it to cut my 11 acre estate and have had no problems until now. I bought a 72" snow blower along with the 455D and this is the first time I have used it. I did my driveway twice and on the second time is when the unit started stalling.