Truck puttering on 1999 Ford Explorer

my 99 ford explorer is puttering when i hit 70 mph. when it first did it, i thought it was the spark plugs. so i changed the plugs and the wires and it stopped for about a month. now, it's doing it again. the only difference is from the 1st time, it would do it when i got to 35mph instead of 70mph. what else could it be?

by in Red Bank, NJ on November 10, 2009
0 answers