I was driving a few days ago and my car developed a miss when I went past half throttle. It pulled a code P0303, number 3 cyl miss. I ordered some new Delco coils from Rock Auto, $28ea, I ordered 2 so I could have a spare. ZZP actually has them for $20 but they couldn't return my call right away when I called at 8am to confirm they had them on stock, at 2pm I was desperate so I called again, got the voice mail so just went with Rock. They did call later that day to be fair and I know they are busy, but by then the part was already in the mail from Rock. In the mean time, I came out from work and that number 3 cyl started missing all the time. Ive heard people say before they had a Subaru sound, thats exactly it!
I needed the car for Sat and Sun, and now even more desperate I started looking at local sources. Advance and Autozone both close to $100ea. The dealer was actually only $60 but they would need to order for Monday. While I was looking on Advance Auto Parts website I noticed something interesting. They had a spark plug boot for my car. I always thought the coil and boot were one pc. It included the boot, spring and a small fuse or resistor type thing. I went out and pulled my coil and tugged on the boot and off it comes....with a crack in it. So what can it hurt? I went to advance, the boot was only $4.99. Put it in, no more miss! The point of my long story, I never knew you could get just the boot, and ill bet many others dont either and just replace the coil, satisfied you fixed the problem, call it a day. Try this first. Might just work......

 

Thanx for passing that info I myself just brought New Coils...

 

Good info.

 

Happened to me as well, massive misfire caused by a cracked boot...auto zone has them it was awesome.

 

Good info man thanks having the same issue now so will try it out

 

Hmmm just had a P0303 yesterday.. ESC off, ENG power reduced, Service Traction, Service ESC.. I may try this shortly. Thanks for the info. Gonna go find proper spark plug gap also.

 

Lmao had the same problem last week while tuning my lnf. The car was having miss fires, and had to buy performance spark plugs (NGK Iridium 40$ for all 4 , pretty expensive) while taking the old ones out, the 3rd one had a cracked boot as well ( not sure if its a cobalt thing, now that I read this thread). Went to orileys 100$ for the hole thing, I was like hell no! And did some research and found just the boot at autozone for 4.99 lol. What a WIN!

 

rockauto

 

Anybody have a part number for the boot at autozone?

 

Here ya go

Duralast/Wireset CP054 at AutoZone.com

 

Haha This thread would've came in handy when I was having 3rd cylinder misfire. I took the car to Chevy and paid them ~$589 to do what I could've done myself for a few bucks. They replaced all the coils, even though it was only the 3rd one that had the issue.
That was back in January. Now I'm just going to do whatever work I can on my own. Only time I'm ever going back to the dealers is if I find I don't feel like doing something, like changing the coolant. I don't wanna put in the effort.