It seems after I changed my plugs, the car now sputters a little during WOT for like 2-5 seconds before smoothing out. I used the OEM NGK plugs that are pre-gapped. The old plugs were the same type, although I didn't check the gap. I double check the new ones which is around .027-.028. Should I close them to like .024-.025? My mods are intake, bov, dp, testpipe, buschur exhaust, greddy EBC at 19PSI on 91octane.

Thanks!

NGK plugs do not come gapped correctly. They are used in other applications besides our cars. What plugs are you running exactly? I would recommend BPR8ES or BPR8EIX if you're still having problems with the standard plugs. The best solution is to buy a coil on plug (COP) setup.

You can close the gap to try preventing blowing out spark, but close it as little as you can. A bigger spark makes for a better burn of the fuel mixture.

I'm using these: NGK Laser Iridium Spark Plug (IGR7A-G) which should be like the OEM from the posts I read. Should I try gapping it first to like .24 or lower before trying a COP setup? With my little mods, would smaller gap help?

You could also try turning your boost controller down a little bit. The cold winter air will sometimes cause higher boost.

I had the same problem as you did, although I wasn't running the same kind of plugs. Close the gap to .024 or so and then take it for a spin at WOT. If it isn't fixed, you can either

a. close the gap even more (which you shouldnt have to)
b. get new plugs (NGK 7's or 8's whatever you prefer)
c. get a COP system (spoolinup sells a good cheap kit that is comparable to the expensive SparkTech)

And try that too, turn the MBC down a couple of turns and see if that helps.

Those plugs are for the IX! You have an 05 right? Throw in a set of BPR8ES and you should be good.

Gap those plugs down to .20 or .18 your putting a damper on your spark with that gap on stock coils.

Are you sure? I checked with the dealership who said its for the 8's. I'll double check but I think my problem is resolved...hopefully. So all the newbies like me who just changed the oil for the first time a month ago, here's what I did today. Based off everyone's replies (thanks everyone!!) and search, I:
1. checked wires, boots and coils with a multimeter. The resistance were within range of the service manual.
2. pulled out the sparkplugs and closed gap to around .22-.23 (hard to judge with those damn autozone plug gapper/gauger
3. pushing some of the hoses to the boost gauge/controller in case they were loose.

the first two pulls 3rd/4th gears I had maybe 1/2 to 1 very light sputter. Can barely feel it.

The last three pulls 3rd/4th/3rd gears, no sputter...nice and smooth.

Also, note the weather was warmer..45F as opposed to the couple days of 15-25F.

I'll keep this post updated in case goes wrong. Again thanks to all who took the time to reply!!

My bad I guess those are the stock plugs for the VIII...regardless I would run an 8 heat range plug. The copper BPR8ES are like $2 a piece or the "upgrade" iridium BPR8EIX are about $8. You really should try either one of those.

<p>No need for iridium for a 8 unless you just like wasting money

I will definitely give those copper a try. I'm assuming under .24 gap as well?

It seems to be working fine now with under between .23-.24. Should I still close it up some more?

If you are running stock coil I would gap them to .20 just to be safe.