I need some help. About one week ago I purchased a 2002 Jeep wrangler (soft top - 4 cyl engine) the jeep has 50000 miles on it what I think is about a 6 in lift and some 35 size tires. I have found the jeep to be extremely slow, it picks up ok but it will not go over 40-45 mph and after a while maybe 50-55 mph I have changed the oil on the car, spark plugs and wires, had injectors clean and changed air filter. Before I do a major investment and further change anything on the jeep I want to know if this is normal or what might my jeep have. I know it might be a heavy car for a 4 cyl but I think it is very slow. Please I need some help!!