my suburban has a misfire in cylinder 5 and i just replaced the cap, rotor, plugs, and wires. i know there are a few about this problem and i know it can be a few different things. When i had it scanned the first time i had the mas airflow, o2 sensor, and #5 misfire. i have talked to a few people and they told me to do compression check and see if its good first. then go from there. Any ideas what should do?