I have a 2003 civic ex. Recently it started to hesitate and the gas mileage went down about 100 miles/ tank. I got it on a computer and I got a cyl. 1 miss fire code (P0301).
I changed out the spark plugs the were pretty bured but I've seen a lot worse. Also I got some STP gas treatment. Then on the next tank of gas I used this stuff called seafoam, bassically the same thing but a little better. So I unpluged my battery to reset the check engine light, and the CEL went off. A week and 1/2 later it starts hesitating again but not as bad. Anyone got some advise. Please help. Thanks

Project_r_dub


There is no plugs its COIL ON PLUG SYSTEM (COP) it has about 120,000 miles and I replaced the plugs @ 70,000 and just a few weeks ago when I first had the problem!

Most misfire situations are either spark plug or coil-related. Try replacing the coil going to cylinder 1.

On an '03 Civic, diconnecting your battery is not going to reset the check engine light. You're most likely running an OBD II computer system, which means you need to reset it with a code scanner.

How many miles are on this car? Is this the first set of plugs you've done? Try doing the plug wires before the coil, if you haven't already.

P.S. I like your quote, Tx :)

There is no plugs its COIL ON PLUG SYSTEM (COP) it has about 120,000 miles and I replaced the plugs @ 70,000 and just a few weeks ago when I first had the problem!

Its going in to a honda shop on tue. Ill update then thax for the help but I need to get to work tues. night I better go to a pro. Thanks

Peace in the mid east

It ended of being the 1st Coil on plug (COP) and a ELD basically a voltage reguilator for newer cars. Hopes this may help someone in the future!