Mechanics

WHAT COULD BE CAUSING MY MISFIRING?

2007 Honda Fit • 103,000 miles

RE: 2007 Honda Fit Sport, 1.5l, 4 cyl.

I've been having an issue with misfiring on this car. Codes are P0300-P0304. I've changed the spark plugs, air filter, and even reduced the gap on the spark plugs thinking the issue was possibly bad ignition coils. I tested all 4 ignition coils on the car and each produced a nice and consistent spark. The spark plugs from cylinder 3 appear to have possible burning type discoloration on them, but other than that, all plugs are dry and unremarkable. I'm not quite sure what to do. It's my only car, so I can't afford not to have it run. Possibly a head gasket? Is there a way to check that before buying a new one? Maybe it's the fuel injectors? Fuel filter?

Please let me know what you think.

The first codes to pop up are 0301, 0302, and 0300 in that order then the rest pop up with a little drive time. Those come on just sitting in my driveway.
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Jayrandall
August 16, 2012.




You replaced the plugs but the coils may still be bad. I would look there first.

Roy

ASEMaster6371
Aug 16, 2012.
I checked the coils. All seem to be functioning normally. I'm about 99% sure it's the head gasket.

Tiny
Jayrandall
Aug 16, 2012.
Coils can break down under load.

Head gasket? What made you think it is this? Very unlikely.

Roy
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ASEMaster6371
Aug 17, 2012.
Hi, I have the same problem on my Fit : (
Did you find what is causing that?

I took my car to the dealer.
They suspected coils but sais that if one's broken, it should not be intermittent. Spark plug seems ok even if they are showing some usure. They were suspecting motor valves; they founded some exhaust valves too tight. Paid 180$ for nothing; my problem still there.

How a head gasket can cause misfire?

Can it be fuel filter, fuel pumps or injector?

Can it be timing chain or belt ; don't know the type in that model?

Tiny
Marc-ericgagnon
Sep 8, 2012.

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