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Greetings Civic fans!

This is my first post. So let me give a little history.

A few weeks ago I bought my first manual transmission vehicle. I wanted a secondary vehicle so I'd stop putting so many miles on my Challenger, and I desperately wanted to learn to drive stick. I'd owned two Civics before, and really liked them. So I scrounged up $4k and bought a 2008 Civic Si with 208k miles on it.

I took her to the shop and had the tranny flushed and oil changed while getting the state inspection done.

But one of the main reasons I wanted another car was so I'd feel safe doing more and more repairs and maintenance myself. Knowing if I break one car I can still get to work on Monday is a huge confidence booster.

I changed out all 16 spark plugs in my Challenger. It's a time-consuming job, but not really all that difficult. After watching a few YouTube videos, the Honda looked like it would be much, much easier. So I tackled that this afternoon.

I met an unexpected roadblock. The coil packs, once unbolted, refused to come out. They were loose, and swiveled freely, but I could not get them out. This boggles my mind. The coil packs in the Challenger came out with zero effort. A simple "pop" and they're out. I tried all sorts of things on the Civic, including wrenches, and pry bars, and eventually they came free.

But there was damage done to the plastic. And one coil pack, (the 1st one on the Left) could no longer accept the wire connector without brute force. They are supposed to just snap in, but the plastic was so deformed, I had to use the wrench again to get the connector to insert deep enough into the coil pack's jack.

I thought I got it connected well, despite the fact I had to use such force. But my engine is throwing a code now. Just one. P0301. Which apparently is misfire at Cylinder 1.

I took her for a little drive to get the code read. The Si is running sluggish, and sounds noticeably different. But there is no bucking or roughness like you might expect with a fully dead cylinder.

Obviously, my first thought was that coil pack. I've purchases a new one, but won't have time to install it until the weekend. I felt like I ought to post this now and get some expert advice before hand. So please, share your thoughts. Tell me what you think.

PS.
Another thing I noticed: the old spark plugs had a WIDE gap. Maybe 4 or 5 times wider than the new plugs, which were around 0.44. Is this due simply to age and wear?

PPS.
These are the spark plugs I bought:
https://www.ebay.com/itm/303396962814

Thanks for your time,

Pinky

 
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You did unplug the coil pack before trying to remove it, right?

Sounds like the coil pack is damaged and no longer working. To test unplug the pack while the engine is running, if you don't hear/feel a noticeable change in engine speed/sound then that cylinder is dead.

0.044" is the correct gap for that engine. Be careful where you buy NGK spark plugs from, I always hear there are lots of knockoffs. It seems Honda engines are particular about what plugs you are using as well.

 
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I made sure to unplug it first. Though I am worried the wire connector may also be damaged when I forced it to connect to the damaged coil pack. I guess I'll know this weekend.

 
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Also, is it possible the misfire is due to how vastly different the gap is between the old plugs and the new? I don't know how this works, but could the computer have been making compensation for the excessive gap, and now it's reading as a misfire?

 
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The new ones are the correct gap, I would have expected issues with the old plugs. Do you still have them? Can you send a picture?

You are seeing misfires on the same cylinder with the visibly damaged coil pack, probably not a coincidence.

 
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I'll try and find them in the trash later.

I know it's weird. But my Si was driving perfectly, with no codes on the old plugs. That's why I'm wondering if the car is just not used to properly gapped plugs.

It also makes me wonder if a past owner installed a tune for very different plugs with very different gaps.

 
Rep Power: 222

It's because of the mangled coil. Get one from a junkyard if you don't want to pay for a new one. And take a close look at the connector on the harness side, make it isn't damaged, bent pins etc. That way if you need a connector you can grab one from the junkyard and cut it off giving yourself plenty of wire for splicing

 
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Thanks for your replies. I'll give an update on Saturday after I see what's what.

 
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Alright, update time!

When I went to install the new coil pack, I saw there was indeed damage done to the cable connector. The clip mechanism had broken off completely. The coil back pins where mangled. No doubt when I wrenched the male and female connections together.

I went ahead and installed the new coil pack. The broken connector went on all the way, this time, but of course, could not latch, due to there being no latch any longer. So I held it on with a rubber band for a temporary fix. Then I cleared the engine codes and started up the vehicle. I didn't drive her around, as I have yet to fasten everything down properly. But I let the Si idle for a few minutes. No more codes came up.

Do you have to actually drive around a bit, or would new misfire codes display even whilst idling?

I have ordered a new cable connector from Honda. I don't look forward to trying to repin the thing, but oh well. I broke it, I should fix it.

 
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Sometimes the engine needs to be under load to misfire, but based on the mangled coil you're probably fine. I would just grab a coil connector from the junkyard and splice it on personally