Multiple Cylinder Misfire on 2006 Toyota Corolla

I recently have had a tune up and now my car has been hard to start as of late. I took it to Advanced Auto Parts to have the starting system tested. The Battery, Starter and Alternator all passed. They also hooked it up to diagnostic computer eventhough there was no check engine light on and received codes that there were random misfires on cylinders 2 and 4. There is no Check Engine Light illuminated. Any Ideas?

1 answer 1 comment
if you recently had a tune up I would check to see if the firing order is right
Okay, I have had My mechanic and Toyota Dealership do Full Inspections of the car. It is not throwing misfire code anymore but is still rough to start when it sits in hot weather for about 2-4 hours. Starts up fine in the morning. Both shops say there is nothing mechanically wrong then why does it give me trouble starting. I had dealership check ECM again since I had them replace in a recall earlier this year they say it is fine. I need help.