sudden rough idle and blinking MIL???

Alright I drive a 97 s-10 4.3x , Ijust recently gave it a tune up about a month and a half ago changing the plugs,wires,cap,rotor,pvc valve,coil,oil,filter,air filter,and replaced the tps sensor also. But here is what happened I was driving and the truck was runnig just fine . Icame to a red light and when I stopped I felt a miss then another, then it started to jump all over the place had to pull off and park my MIL light came on and started blinking.Does anyone know what could cause this sudden misfiring?I checked with autozone loaner scan tool and p0300 random misfire is all it came up with.and it was'nt raining either.