95 Ford ranger, 140,000 miles. I have a misfire in cyl. 2 and 4, (I had the codes read at auto zone) I've changed spark plugs, wires, TPS, coil packs, computer, inlectors, fuel filter, air filter, etc. The misfire is intermitant though. It may misfire halfway through 1st gear, then stop, then start again half way through 2nd. The check engine light is always on but when it misfires really bad the it flashes. Please help.