Today I just picked up a set of Spark Tech's COP ignition system off craigslist for great deal. It's in amazing condition and look great in the engine bay. After install, there is a noticeable difference in the idle, the sound of the exhaust, and the smoothness in the entire rev range. Even with the AC on, shifting has improved. Overall a great upgrade, especially since I'll be looking for more power in the near future.

There is one issue though. The reason I upgraded from my stock coilpacks was to solve the issue of misfire (p0300) under a slight load (0-5psi boost) in 5th gear. I'm still getting a check engine light every now and then because of it and I don't know why. I use NGK bpr7es gapped at .025 along with bolt ons tuned on 24psi on 91oct. I also put in fresh Amsoil and spark plugs as of last week.

Possible problem areas could be:
-Twinvent BOV
-Spark plugs or their gap
-The tune

Any input would be appreciated.

 

Close the gap to .022, are they fresh plugs?

 

Yes. I've been using these for the last 2 years. Should I try the bpr8es or a similar one-step colder plug?

 

I actually run BR8es plugs with the same spark tech cop and run 100% denatured alcohol and have no issues, I gap my plugs at .022.

 

As u stated, possible issue could jest be a retune. Chances are you will gain more so its a win/win.

 

Does the fact that I have a stock head/turbo on 91 matter if i'm going to be using the br8es though?

 

I'm tuned on 91 as well, I use ngk bpr8es gapped at .022. Copper plugs should be changed with every oil change. They foul out pretty regularly.

 

No. None what so ever. I have the same set up you have and zero issues. It's something besides the COP unless one of them is flaky which is unlikely.

If you had the issue before and that didn't fix it you have some other problem it's that easy.

 

You must be made out of money, not that plugs are overly expensive but you should NEVER have to replace them that frequently unless you are racing with them. Even then that would be excessive.

I guess as long as it works for you it's all good though. You have issues if you are replacing them that often though.

 

Haha out of money, oil alone cost more than plugs. Ngk coppers cost me about 10$ for 4. So why not change them every oil change? But you are right it might be excessive. I just do it for the piece of mind, if they were irdiums I would use them for awhile.

 

I do the same with my plugs, as running the 8's they do tend to foul out easier. I have heard by many that on a highly tuned car that the ngk coppers only last from 3000-5000 miles.

 

I usually change my spark plugs every 5000 miles because why not, it's $10. Anyways, I guess I'll try .022 and a retune.

 

That code popping up is a common issue. Just turn it off in the ecu. There are several threads in the ecuflash section about it.

 

Okay, but clearing a CEL isn't gonna make the misfire go away.

 

Do you believe you're having a genuine misfire issue? How often does your car crackle, pop and bang?