[mellowboy]

Originally Posted by mattgo79

Hello, folks. I have a 2003 Civic EX Coupe with about 122,000 miles. About nine months ago, my car started sputtering, so I took it to my local mechanic. Long story short and about $400 after, my car started sputtering again. So thus far, my mechanic had changed the EGR valve and retorqued my spark plugs. Ran fine for a couple of months and then my car started doing it again. I replaced all the spark plugs, and again, my car started to run fine again. Then... it started sputtering once again, my check engine light came on and so instead of taking it to the mechanic, I went to Auto Zone so they'd read the error codes (for free). So my car was misfiring on Cylinder 1. I replaced the coil on Cylinder 1 and the sputtering went away. Then four weeks later, my car started sputtering again! I replaced all of the coils, and the sputtering went away for about a day, then it started sputtering yet again.

What on earth could be happening?

Sounds like a spark issue to me. You need to take it to the Honda dealer to have them check out your problem more accurately. I haven't really been researching 01-05 hondas lately but from what it sounds like, it's spark issues or not getting enough air/fuel.