Diagnosis?
11-15-2016
#1
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Diagnosis?
My son's 2005 ex 4cyl 1.7L. Cat conv was burned up. CEL on. I needed to get it to pass ins. I changed out new Cat Conv, Ig coils, plugs, both O2 sens. CEL cleared passed insp. Drove it approx 100 miles and started it up and noticed it idling rough. Drove it and CEL came back on blinking with burn smell. Close enough that I got it home. Code read P0303 found burnt cyl 3 elect connection with Ignition coil prong stuck in burned connector. Since I just changed all these coils out any idea what the issue is? Is it a wiring harness issue? Did I by chance even though new put a bad coil back in? Just a note the spark plug looks ok. Slight smell of gas on igniter end. I have never worked on a Honda so any suggestions on what the issue/next steps should be are greatly appreciated.
11-15-2016
#2
If you think a good mechanic is expensive, try hiring a bad one
Re: Diagnosis?
Fix the wiring, whatever it takes. Maybe go to a you-pull-it yard and get a harness or pigtail and wire it up.
Grab one of the original coils you took off and use it. They aren't a high failure rate item, so I'd expect you didn't need to replace them in the first place unless there was a misfire problem to begin with.
Hope the new cat wasn't damaged from driving with a misfiring cylinder.
Grab one of the original coils you took off and use it. They aren't a high failure rate item, so I'd expect you didn't need to replace them in the first place unless there was a misfire problem to begin with.
Hope the new cat wasn't damaged from driving with a misfiring cylinder.
11-15-2016
#4
Dr Krieger of Modification
Re: Diagnosis?
You could also grab a multimeter and a test light.
Check the wiring and see if it is getting signal to fire properly, that you have proper voltage and ground, and that the amperage is not too high.
Also check to see if the electrical connector some how got moisture in it and that the new one is fully clicked together when you replace it.
Check the wiring and see if it is getting signal to fire properly, that you have proper voltage and ground, and that the amperage is not too high.
Also check to see if the electrical connector some how got moisture in it and that the new one is fully clicked together when you replace it.
11-19-2016
#5
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Thank you for the recommendations. I went to the junk yard and pulled a wiring harness. Spliced in a ignition coil connector and put one of the old ignition coils back in. Started it up and it ran fine. Hoping it was just a bad coil/ wiring. I will do a compression check before serious driving. So far so good. Thanks for the feedback!
11-19-2016
#6
If you think a good mechanic is expensive, try hiring a bad one
Re: Diagnosis?
Make sure to erase codes.
If it has low compression, low enough to be a problem, you will keep seeing misfire codes reset on that cylinder.
Methinks crappy discount coil caused the problem.. Might want to go back to all OE coils instead.
If it has low compression, low enough to be a problem, you will keep seeing misfire codes reset on that cylinder.
Methinks crappy discount coil caused the problem.. Might want to go back to all OE coils instead.
