my 2000 silverado 4.8 only has 9700 miles on it a few weeks ago i started it there was a miss like a bad plug /when i shut it off and restarted it it was fine. today the miss came back and service engine soon light came on i cheched plug wires into coil packs all look good no corrosion every thing is original on truck like i said only 9700 miles /truck was given to me last november with 8400 miles on it / is there anyway to check it without a scanner to read codes