[jserv]

I have [ffrocks]a 2002 SE wagon with nearly 175K on it. Recently, I was on a trip back from Chicago and the Check Engine Light started blinking (It is always on). The car was slow to accelerate, shifted hard between 2nd and 3rd, and my gas mileage took a nosedive. The check engine light would go solid if I drove around 55 mph for a bit. I ran the codes and got a p0303 (cylinder 3 misfire) and p0420(catalytic efficiency below threshold).

After a few weeks, I got around to troubleshooting it. Changed the plugs and valve cover gasket. The car wouldn't start at all. So I moved on to the coil pack. After changing the coil pack the car started and ran beautifully. Also, a small miracle, no check engine light!! I put about 200 miles (mostly highway) and the check engine light came back on(solid this time). Ran the codes today and the p0303 and p0420 are back.

I've read other websites and forums and haven't found any good fixes. Is there something that could cause the coil packs to burn out? (I replaced it when I bought the car 2 years ago) Is this my catalytic converter, o2 sensor? I love my focus, but don't want to replace coil packs annually![ffrocks]

Thanks in advance for the help guys. This website has been a life saver!

 

[amc49]

Buy better quality coils, the crap ones can fail in a week.....................the cars have trouble with even the best of the best once they get some time on them. So no shortchanging there. The coil connector right at coil sometimes breaks wires too.

No mention of wires, they often fail when yanking them to change plugs. The conductor inside is string. Just the act of pulling them fails them internally.

 

[jserv]

Thanks AMC. When you refer to better quality coils...any particular brands that you have had success with in your zetec's?

 

[amc49]

Motorcraft. Wells. Standard. Mcraft is the best.

 

[Leora83]

When the CEL blinks, it's a good idea to stop driving the car as soon as possible. That means you're getting enough misfire to do damage.

Check that coil wiring harness. I've replaced it on both my Zetecs.