I had a CEL and a definate misfire. I went to AutoZone for a code read. They told me misfire cyl#6. So I changed all 8 plugs (boy, what a hassle!!!!!) and put a new coil on #6. Drove a few days, CEL came back. This time they said misfire cyl#4 and #5 plus a random misfire. Problem is erratic, but def happens when going uphill at any speed and doesn't feel that same as a misfire. Sluggish, hesitation.

Today CEL began flashing while I was going uphill at betw 35 and 40MPH. I gunned it, got over the hill, CEL stopped flashing and went out. Will that flashing CEL produce a code in memory that will come up next time I can get it checked?

Is the fuel pump a possibility?

Or did I disturb some super sensitive fuel/air hose/line while I was saving myself $450 on a garage tune up.

Most of the time it runs fine, but randomly it hesitates.

 

If your at the 100,000 mile tune up you need a little more than a set of plugs, but it should store a code after a few seconds of seeing the light on.