i have a 1993 sc300 and i went to work this morning and all is fine.... but i go to leave and it stumbles and jerks pretty hard when you barely press the gas in i thought it might be the fuel but its not i changed the filter too plus checked the timing??? i think it might be the cat conv's cause i think they have a slight clog cause i can smell it sometimes but i am stumped??? anybody have any suggestions please?????????