Just bought a 95 with 480,000 miles on it. Lots of power most of the time. sometimes little power. exhaust pipe broken off in front of the catastrophic converter when I bought it, ran fine in the mountains (7500 feet). When I took it down the hill, it ran fine until the first shut off, then no power. Took it home, lots of power the next day, replaced fuel filter. No power the next day, the next day lots of power. ???any advice appreciated.