DOG3101

So for the past month or so, my TCS light starts flashing while normal driving to work when I hit a bump. It doesn't flash for very long, maybe a couple seconds. I continue on and have noticed that there seems the engine seems to be missing every so often. A week later, I get a check engine light. After reading the codes, shows a misfire (p0307). So I've changed the coil and spark plug and everything seems to work for about a week when it happens again. This time it's a different (p0305). So far I have had this happen 3 times now and have changed the coil & spark plug on 5,6,7. Yesterday, the TCS light flashed again and I'm just waiting on the check engine light to show. I am replacing the rest of the coils and plugs this afternoon. Is there something else I should be checking? What is the relation with the TCS light & misfires? Your help would be appreciated, thanks!